From 2d006a847235a3308510f638a27b8d12df1d1134 Mon Sep 17 00:00:00 2001
From: Jordi Boggiano <j.boggiano@seld.be>
Date: Tue, 19 Apr 2022 21:49:03 +0200
Subject: [PATCH] Convert level/levelName to enums (#1656)

---
 .gitignore                                    |   2 +-
 .php_cs => .php-cs-fixer.php                  |  16 +-
 README.md                                     |   4 +-
 doc/01-usage.md                               |   8 +-
 doc/04-extending.md                           |   2 +-
 doc/sockets.md                                |   3 +-
 src/Monolog/Formatter/ChromePHPFormatter.php  |  28 ++--
 src/Monolog/Formatter/FlowdockFormatter.php   |   4 +-
 src/Monolog/Formatter/FluentdFormatter.php    |   6 +-
 .../Formatter/GelfMessageFormatter.php        |  32 ++--
 src/Monolog/Formatter/HtmlFormatter.php       |  33 ++--
 src/Monolog/Formatter/WildfireFormatter.php   |  40 ++---
 src/Monolog/Handler/AbstractHandler.php       |  31 ++--
 .../Handler/AbstractProcessingHandler.php     |   3 -
 src/Monolog/Handler/AbstractSyslogHandler.php |  69 ++++----
 src/Monolog/Handler/AmqpHandler.php           |   6 +-
 src/Monolog/Handler/BufferHandler.php         |   7 +-
 src/Monolog/Handler/ChromePHPHandler.php      |   6 +-
 src/Monolog/Handler/CouchDBHandler.php        |   4 +-
 src/Monolog/Handler/CubeHandler.php           |   4 +-
 src/Monolog/Handler/DeduplicationHandler.php  |  18 +-
 .../Handler/DoctrineCouchDBHandler.php        |   4 +-
 src/Monolog/Handler/DynamoDbHandler.php       |   4 +-
 src/Monolog/Handler/ElasticaHandler.php       |   4 +-
 src/Monolog/Handler/ElasticsearchHandler.php  |   4 +-
 src/Monolog/Handler/ErrorLogHandler.php       |   4 +-
 src/Monolog/Handler/FilterHandler.php         |  47 +++---
 .../ChannelLevelActivationStrategy.php        |  33 ++--
 .../ErrorLevelActivationStrategy.php          |  20 +--
 src/Monolog/Handler/FingersCrossedHandler.php |  22 +--
 src/Monolog/Handler/FleepHookHandler.php      |   4 +-
 src/Monolog/Handler/FlowdockHandler.php       |   4 +-
 src/Monolog/Handler/GelfHandler.php           |   4 +-
 src/Monolog/Handler/HandlerInterface.php      |   2 -
 src/Monolog/Handler/IFTTTHandler.php          |   4 +-
 src/Monolog/Handler/InsightOpsHandler.php     |   4 +-
 src/Monolog/Handler/LogEntriesHandler.php     |   4 +-
 src/Monolog/Handler/LogglyHandler.php         |   4 +-
 src/Monolog/Handler/LogmaticHandler.php       |   4 +-
 src/Monolog/Handler/MailHandler.php           |   4 +-
 src/Monolog/Handler/MandrillHandler.php       |   4 +-
 src/Monolog/Handler/MongoDBHandler.php        |   4 +-
 src/Monolog/Handler/NativeMailerHandler.php   |   4 +-
 src/Monolog/Handler/NewRelicHandler.php       |   4 +-
 src/Monolog/Handler/NullHandler.php           |  22 +--
 src/Monolog/Handler/OverflowHandler.php       |  25 +--
 src/Monolog/Handler/PHPConsoleHandler.php     |   8 +-
 src/Monolog/Handler/ProcessHandler.php        |   4 +-
 src/Monolog/Handler/PsrHandler.php            |   8 +-
 src/Monolog/Handler/PushoverHandler.php       |  55 +++---
 src/Monolog/Handler/RedisHandler.php          |   4 +-
 src/Monolog/Handler/RedisPubSubHandler.php    |   6 +-
 src/Monolog/Handler/RollbarHandler.php        |  38 +++--
 src/Monolog/Handler/RotatingFileHandler.php   |   4 +-
 src/Monolog/Handler/SamplingHandler.php       |   1 -
 src/Monolog/Handler/SendGridHandler.php       |   4 +-
 src/Monolog/Handler/Slack/SlackRecord.php     |  22 +--
 src/Monolog/Handler/SlackHandler.php          |   4 +-
 src/Monolog/Handler/SlackWebhookHandler.php   |   4 +-
 src/Monolog/Handler/SocketHandler.php         |   4 +-
 src/Monolog/Handler/SqsHandler.php            |   4 +-
 src/Monolog/Handler/StreamHandler.php         |   4 +-
 src/Monolog/Handler/SyslogHandler.php         |   6 +-
 src/Monolog/Handler/SyslogUdpHandler.php      |   6 +-
 src/Monolog/Handler/TelegramBotHandler.php    |   4 +-
 src/Monolog/Handler/TestHandler.php           |  51 ++----
 src/Monolog/Handler/ZendMonitorHandler.php    |  53 +++---
 src/Monolog/Level.php                         | 127 ++++++++++++++
 src/Monolog/LevelName.php                     |  53 ++++++
 src/Monolog/LogRecord.php                     |  31 ++--
 src/Monolog/Logger.php                        | 126 ++++++--------
 src/Monolog/Processor/GitProcessor.php        |  14 +-
 .../Processor/IntrospectionProcessor.php      |  15 +-
 src/Monolog/Processor/MercurialProcessor.php  |  16 +-
 src/Monolog/SignalHandler.php                 |  13 +-
 src/Monolog/Test/TestCase.php                 |  21 +--
 tests/Monolog/ErrorHandlerTest.php            |   2 +-
 .../Formatter/ChromePHPFormatterTest.php      |  12 +-
 .../Formatter/ElasticaFormatterTest.php       |   4 +-
 .../Formatter/ElasticsearchFormatterTest.php  |   4 +-
 .../Formatter/FlowdockFormatterTest.php       |   6 +-
 .../Formatter/FluentdFormatterTest.php        |   6 +-
 .../Formatter/GelfMessageFormatterTest.php    |  18 +-
 tests/Monolog/Formatter/JsonFormatterTest.php |  18 +-
 tests/Monolog/Formatter/LineFormatterTest.php |  30 ++--
 .../Formatter/LogstashFormatterTest.php       |  19 ++-
 .../Formatter/MongoDBFormatterTest.php        |  21 +--
 .../Formatter/NormalizerFormatterTest.php     |  27 +--
 .../Formatter/WildfireFormatterTest.php       |  12 +-
 tests/Monolog/Handler/AbstractHandlerTest.php |  18 +-
 .../Handler/AbstractProcessingHandlerTest.php |  16 +-
 tests/Monolog/Handler/AmqpHandlerTest.php     |   6 +-
 .../Handler/BrowserConsoleHandlerTest.php     |  24 +--
 tests/Monolog/Handler/BufferHandlerTest.php   |  46 ++---
 .../Monolog/Handler/ChromePHPHandlerTest.php  |  20 +--
 tests/Monolog/Handler/CouchDBHandlerTest.php  |   4 +-
 .../Handler/DeduplicationHandlerTest.php      |  38 ++---
 .../Handler/DoctrineCouchDBHandlerTest.php    |   6 +-
 tests/Monolog/Handler/ElasticaHandlerTest.php |   8 +-
 .../Handler/ElasticsearchHandlerTest.php      |   6 +-
 tests/Monolog/Handler/ErrorLogHandlerTest.php |   8 +-
 .../Handler/FallbackGroupHandlerTest.php      |  26 +--
 tests/Monolog/Handler/FilterHandlerTest.php   |  93 ++++++-----
 .../Handler/FingersCrossedHandlerTest.php     |  88 +++++-----
 tests/Monolog/Handler/FirePHPHandlerTest.php  |  14 +-
 .../Monolog/Handler/FleepHookHandlerTest.php  |   6 +-
 tests/Monolog/Handler/FlowdockHandlerTest.php |   6 +-
 tests/Monolog/Handler/GelfHandlerTest.php     |   8 +-
 tests/Monolog/Handler/GroupHandlerTest.php    |  20 +--
 .../Monolog/Handler/InsightOpsHandlerTest.php |   6 +-
 .../Monolog/Handler/LogEntriesHandlerTest.php |   6 +-
 tests/Monolog/Handler/LogmaticHandlerTest.php |   6 +-
 tests/Monolog/Handler/MailHandlerTest.php     |  10 +-
 .../Handler/NativeMailerHandlerTest.php       |   6 +-
 tests/Monolog/Handler/NewRelicHandlerTest.php |  42 ++---
 tests/Monolog/Handler/NoopHandlerTest.php     |  12 +-
 tests/Monolog/Handler/NullHandlerTest.php     |   6 +-
 tests/Monolog/Handler/OverflowHandlerTest.php |  40 ++---
 .../Monolog/Handler/PHPConsoleHandlerTest.php |   3 +-
 tests/Monolog/Handler/ProcessHandlerTest.php  |  20 +--
 tests/Monolog/Handler/PsrHandlerTest.php      |  29 ++--
 tests/Monolog/Handler/PushoverHandlerTest.php |  22 +--
 tests/Monolog/Handler/RedisHandlerTest.php    |  14 +-
 .../Handler/RedisPubSubHandlerTest.php        |   6 +-
 tests/Monolog/Handler/RollbarHandlerTest.php  |   8 +-
 .../Monolog/Handler/Slack/SlackRecordTest.php |  61 ++++---
 tests/Monolog/Handler/SlackHandlerTest.php    |  32 ++--
 .../Handler/SlackWebhookHandlerTest.php       |   9 +-
 tests/Monolog/Handler/SocketHandlerTest.php   |   4 +-
 tests/Monolog/Handler/StreamHandlerTest.php   |  16 +-
 tests/Monolog/Handler/SyslogHandlerTest.php   |   4 +-
 .../Monolog/Handler/SyslogUdpHandlerTest.php  |   3 +-
 .../Handler/TelegramBotHandlerTest.php        |   4 +-
 tests/Monolog/Handler/TestHandlerTest.php     |  24 +--
 .../Handler/WhatFailureGroupHandlerTest.php   |  22 +--
 .../Handler/ZendMonitorHandlerTest.php        |   8 +-
 tests/Monolog/LoggerTest.php                  | 157 ++++++++----------
 .../Processor/IntrospectionProcessorTest.php  |  14 +-
 138 files changed, 1297 insertions(+), 1216 deletions(-)
 rename .php_cs => .php-cs-fixer.php (85%)
 create mode 100644 src/Monolog/Level.php
 create mode 100644 src/Monolog/LevelName.php

diff --git a/.gitignore b/.gitignore
index a3ec4bab..9418cccf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,6 @@ composer.phar
 phpunit.xml
 composer.lock
 .DS_Store
-.php_cs.cache
+.php-cs-fixer.cache
 .hg
 .phpunit.result.cache
diff --git a/.php_cs b/.php-cs-fixer.php
similarity index 85%
rename from .php_cs
rename to .php-cs-fixer.php
index 6fc3ca2e..2638adc7 100644
--- a/.php_cs
+++ b/.php-cs-fixer.php
@@ -17,10 +17,8 @@ $finder = PhpCsFixer\Finder::create()
     ->in(__DIR__.'/tests')
 ;
 
-return PhpCsFixer\Config::create()
-    ->setUsingCache(true)
-    ->setRiskyAllowed(true)
-    ->setRules(array(
+$config = new PhpCsFixer\Config();
+return $config->setRules(array(
         '@PSR2' => true,
         // some rules disabled as long as 1.x branch is maintained
         'binary_operator_spaces' => array(
@@ -30,11 +28,11 @@ return PhpCsFixer\Config::create()
         'cast_spaces' => ['space' => 'single'],
         'header_comment' => ['header' => $header],
         'include' => true,
-        'class_attributes_separation' => ['elements' => ['method']],
+        'class_attributes_separation' => array('elements' => array('method' => 'one', 'trait_import' => 'none')),
         'no_blank_lines_after_class_opening' => true,
         'no_blank_lines_after_phpdoc' => true,
         'no_empty_statement' => true,
-        'no_extra_consecutive_blank_lines' => true,
+        'no_extra_blank_lines' => true,
         'no_leading_import_slash' => true,
         'no_leading_namespace_whitespace' => true,
         'no_trailing_comma_in_singleline_array' => true,
@@ -49,13 +47,15 @@ return PhpCsFixer\Config::create()
         //'phpdoc_scalar' => true,
         'phpdoc_trim' => true,
         //'phpdoc_types' => true,
-        'psr0' => true,
+        'psr_autoloading' => ['dir' => 'src'],
         //'array_syntax' => array('syntax' => 'short'),
         'declare_strict_types' => true,
         'single_blank_line_before_namespace' => true,
         'standardize_not_equals' => true,
         'ternary_operator_spaces' => true,
-        'trailing_comma_in_multiline_array' => true,
+        'trailing_comma_in_multiline' => true,
     ))
+    ->setUsingCache(true)
+    ->setRiskyAllowed(true)
     ->setFinder($finder)
 ;
diff --git a/README.md b/README.md
index bfcae0c0..8a431d7e 100644
--- a/README.md
+++ b/README.md
@@ -33,7 +33,7 @@ use Monolog\Handler\StreamHandler;
 
 // create a log channel
 $log = new Logger('name');
-$log->pushHandler(new StreamHandler('path/to/your.log', Logger::WARNING));
+$log->pushHandler(new StreamHandler('path/to/your.log', Level::Warning));
 
 // add records to the log
 $log->warning('Foo');
@@ -50,7 +50,7 @@ $log->error('Bar');
 
 ## Support Monolog Financially
 
-Get supported Monolog and help fund the project with the [Tidelift Subscription](https://tidelift.com/subscription/pkg/packagist-monolog-monolog?utm_source=packagist-monolog-monolog&utm_medium=referral&utm_campaign=enterprise) or via [GitHub sponsorship](https://github.com/sponsors/Seldaek). 
+Get supported Monolog and help fund the project with the [Tidelift Subscription](https://tidelift.com/subscription/pkg/packagist-monolog-monolog?utm_source=packagist-monolog-monolog&utm_medium=referral&utm_campaign=enterprise) or via [GitHub sponsorship](https://github.com/sponsors/Seldaek).
 
 Tidelift delivers commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use.
 
diff --git a/doc/01-usage.md b/doc/01-usage.md
index 89e0fe7f..54d7b36c 100644
--- a/doc/01-usage.md
+++ b/doc/01-usage.md
@@ -90,7 +90,7 @@ use Monolog\Handler\FirePHPHandler;
 // Create the logger
 $logger = new Logger('my_logger');
 // Now add some handlers
-$logger->pushHandler(new StreamHandler(__DIR__.'/my_app.log', Logger::DEBUG));
+$logger->pushHandler(new StreamHandler(__DIR__.'/my_app.log', Level::Debug));
 $logger->pushHandler(new FirePHPHandler());
 
 // You can now use your logger
@@ -170,7 +170,7 @@ use Monolog\Handler\StreamHandler;
 use Monolog\Handler\FirePHPHandler;
 
 // Create some handlers
-$stream = new StreamHandler(__DIR__.'/my_app.log', Logger::DEBUG);
+$stream = new StreamHandler(__DIR__.'/my_app.log', Level::Debug);
 $firephp = new FirePHPHandler();
 
 // Create the main logger of the app
@@ -205,7 +205,7 @@ You can choose between predefined formatter classes or write your own (e.g. a mu
 > A very useful formatter to look at, is the `LineFormatter`.
 >
 > This formatter, as its name might indicate, is able to return a lineal string representation of the log record provided.
-> 
+>
 > It is also capable to interpolate values from the log record, into the output format template used by the formatter to generate the final result, and in order to do it, you need to provide the log record values you are interested in, in the output template string using the form %value%, e.g: "'%context.foo% => %extra.foo%'" , in this example the values $record->context["foo"] and $record->extra["foo"] will be rendered as part of th final result.
 
 In the following example, we demonstrate how to:
@@ -229,7 +229,7 @@ $output = "%datetime% > %level_name% > %message% %context% %extra%\n";
 $formatter = new LineFormatter($output, $dateFormat);
 
 // Create a handler
-$stream = new StreamHandler(__DIR__.'/my_app.log', Logger::DEBUG);
+$stream = new StreamHandler(__DIR__.'/my_app.log', Level::Debug);
 $stream->setFormatter($formatter);
 
 // bind it to a logger object
diff --git a/doc/04-extending.md b/doc/04-extending.md
index 0a2ad338..49cded91 100644
--- a/doc/04-extending.md
+++ b/doc/04-extending.md
@@ -30,7 +30,7 @@ class PDOHandler extends AbstractProcessingHandler
     private $pdo;
     private $statement;
 
-    public function __construct(PDO $pdo, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(PDO $pdo, $level = Level::Debug, bool $bubble = true)
     {
         $this->pdo = $pdo;
         parent::__construct($level, $bubble);
diff --git a/doc/sockets.md b/doc/sockets.md
index c1190c23..d02f722d 100644
--- a/doc/sockets.md
+++ b/doc/sockets.md
@@ -26,7 +26,7 @@ $handler = new SocketHandler('unix:///var/log/httpd_app_log.socket');
 $handler->setPersistent(true);
 
 // Now add the handler
-$logger->pushHandler($handler, Logger::DEBUG);
+$logger->pushHandler($handler, Level::Debug);
 
 // You can now use your logger
 $logger->info('My logger is now ready');
@@ -36,4 +36,3 @@ $logger->info('My logger is now ready');
 In this example, using syslog-ng, you should see the log on the log server:
 
     cweb1 [2012-02-26 00:12:03] my_logger.INFO: My logger is now ready [] []
-
diff --git a/src/Monolog/Formatter/ChromePHPFormatter.php b/src/Monolog/Formatter/ChromePHPFormatter.php
index e855d64a..0551e1a2 100644
--- a/src/Monolog/Formatter/ChromePHPFormatter.php
+++ b/src/Monolog/Formatter/ChromePHPFormatter.php
@@ -11,6 +11,7 @@
 
 namespace Monolog\Formatter;
 
+use Monolog\Level;
 use Monolog\Logger;
 use Monolog\LogRecord;
 
@@ -24,18 +25,21 @@ class ChromePHPFormatter implements FormatterInterface
     /**
      * Translates Monolog log levels to Wildfire levels.
      *
-     * @var array<int, 'log'|'info'|'warn'|'error'>
+     * @return 'log'|'info'|'warn'|'error'
      */
-    private $logLevels = [
-        Logger::DEBUG     => 'log',
-        Logger::INFO      => 'info',
-        Logger::NOTICE    => 'info',
-        Logger::WARNING   => 'warn',
-        Logger::ERROR     => 'error',
-        Logger::CRITICAL  => 'error',
-        Logger::ALERT     => 'error',
-        Logger::EMERGENCY => 'error',
-    ];
+    private function toWildfireLevel(Level $level): string
+    {
+        return match ($level) {
+            Level::Debug     => 'log',
+            Level::Info      => 'info',
+            Level::Notice    => 'info',
+            Level::Warning   => 'warn',
+            Level::Error     => 'error',
+            Level::Critical  => 'error',
+            Level::Alert     => 'error',
+            Level::Emergency => 'error',
+        };
+    }
 
     /**
      * {@inheritDoc}
@@ -64,7 +68,7 @@ class ChromePHPFormatter implements FormatterInterface
             $record->channel,
             $message,
             $backtrace,
-            $this->logLevels[$record->level],
+            $this->toWildfireLevel($record->level),
         ];
     }
 
diff --git a/src/Monolog/Formatter/FlowdockFormatter.php b/src/Monolog/Formatter/FlowdockFormatter.php
index 6518976e..83a73c81 100644
--- a/src/Monolog/Formatter/FlowdockFormatter.php
+++ b/src/Monolog/Formatter/FlowdockFormatter.php
@@ -45,7 +45,7 @@ class FlowdockFormatter implements FormatterInterface
     {
         $tags = [
             '#logs',
-            '#' . strtolower($record->levelName),
+            '#' . strtolower($record->levelName->value),
             '#' . $record->channel,
         ];
 
@@ -56,7 +56,7 @@ class FlowdockFormatter implements FormatterInterface
         $subject = sprintf(
             'in %s: %s - %s',
             $this->source,
-            $record->levelName,
+            $record->levelName->value,
             $this->getShortMessage($record->message)
         );
 
diff --git a/src/Monolog/Formatter/FluentdFormatter.php b/src/Monolog/Formatter/FluentdFormatter.php
index 31d4d5e2..ce596df6 100644
--- a/src/Monolog/Formatter/FluentdFormatter.php
+++ b/src/Monolog/Formatter/FluentdFormatter.php
@@ -60,7 +60,7 @@ class FluentdFormatter implements FormatterInterface
     {
         $tag = $record->channel;
         if ($this->levelTag) {
-            $tag .= '.' . strtolower($record->levelName);
+            $tag .= '.' . strtolower($record->levelName->value);
         }
 
         $message = [
@@ -70,8 +70,8 @@ class FluentdFormatter implements FormatterInterface
         ];
 
         if (!$this->levelTag) {
-            $message['level'] = $record->level;
-            $message['level_name'] = $record->levelName;
+            $message['level'] = $record->level->value;
+            $message['level_name'] = $record->levelName->value;
         }
 
         return Utils::jsonEncode([$tag, $record->datetime->getTimestamp(), $message]);
diff --git a/src/Monolog/Formatter/GelfMessageFormatter.php b/src/Monolog/Formatter/GelfMessageFormatter.php
index bf24b372..5d2d9de8 100644
--- a/src/Monolog/Formatter/GelfMessageFormatter.php
+++ b/src/Monolog/Formatter/GelfMessageFormatter.php
@@ -11,6 +11,7 @@
 
 namespace Monolog\Formatter;
 
+use Monolog\Level;
 use Monolog\Logger;
 use Gelf\Message;
 use Monolog\Utils;
@@ -21,8 +22,6 @@ use Monolog\LogRecord;
  * @see http://docs.graylog.org/en/latest/pages/gelf.html
  *
  * @author Matt Lehner <mlehner@gmail.com>
- *
- * @phpstan-import-type Level from \Monolog\Logger
  */
 class GelfMessageFormatter extends NormalizerFormatter
 {
@@ -50,21 +49,20 @@ class GelfMessageFormatter extends NormalizerFormatter
 
     /**
      * Translates Monolog log levels to Graylog2 log priorities.
-     *
-     * @var array<int, int>
-     *
-     * @phpstan-var array<Level, int>
      */
-    private $logLevels = [
-        Logger::DEBUG     => 7,
-        Logger::INFO      => 6,
-        Logger::NOTICE    => 5,
-        Logger::WARNING   => 4,
-        Logger::ERROR     => 3,
-        Logger::CRITICAL  => 2,
-        Logger::ALERT     => 1,
-        Logger::EMERGENCY => 0,
-    ];
+    private function getGraylog2Priority(Level $level): int
+    {
+        return match ($level) {
+            Level::Debug     => 7,
+            Level::Info      => 6,
+            Level::Notice    => 5,
+            Level::Warning   => 4,
+            Level::Error     => 3,
+            Level::Critical  => 2,
+            Level::Alert     => 1,
+            Level::Emergency => 0,
+        };
+    }
 
     public function __construct(?string $systemName = null, ?string $extraPrefix = null, string $contextPrefix = 'ctxt_', ?int $maxLength = null)
     {
@@ -101,7 +99,7 @@ class GelfMessageFormatter extends NormalizerFormatter
             ->setTimestamp($record->datetime)
             ->setShortMessage((string) $record->message)
             ->setHost($this->systemName)
-            ->setLevel($this->logLevels[$record->level]);
+            ->setLevel($this->getGraylog2Priority($record->level));
 
         // message length + system name length + 200 for padding / metadata
         $len = 200 + strlen((string) $record->message) + strlen($this->systemName);
diff --git a/src/Monolog/Formatter/HtmlFormatter.php b/src/Monolog/Formatter/HtmlFormatter.php
index d534755e..2841a38e 100644
--- a/src/Monolog/Formatter/HtmlFormatter.php
+++ b/src/Monolog/Formatter/HtmlFormatter.php
@@ -11,6 +11,7 @@
 
 namespace Monolog\Formatter;
 
+use Monolog\Level;
 use Monolog\Logger;
 use Monolog\Utils;
 use Monolog\LogRecord;
@@ -26,19 +27,20 @@ class HtmlFormatter extends NormalizerFormatter
 {
     /**
      * Translates Monolog log levels to html color priorities.
-     *
-     * @var array<int, string>
      */
-    protected $logLevels = [
-        Logger::DEBUG     => '#CCCCCC',
-        Logger::INFO      => '#28A745',
-        Logger::NOTICE    => '#17A2B8',
-        Logger::WARNING   => '#FFC107',
-        Logger::ERROR     => '#FD7E14',
-        Logger::CRITICAL  => '#DC3545',
-        Logger::ALERT     => '#821722',
-        Logger::EMERGENCY => '#000000',
-    ];
+    protected function getLevelColor(Level $level): string
+    {
+        return match ($level) {
+            Level::Debug     => '#CCCCCC',
+            Level::Info      => '#28A745',
+            Level::Notice    => '#17A2B8',
+            Level::Warning   => '#FFC107',
+            Level::Error     => '#FD7E14',
+            Level::Critical  => '#DC3545',
+            Level::Alert     => '#821722',
+            Level::Emergency => '#000000',
+        };
+    }
 
     /**
      * @param string|null $dateFormat The format of the timestamp: one supported by DateTime::format
@@ -69,14 +71,13 @@ class HtmlFormatter extends NormalizerFormatter
      * Create a HTML h1 tag
      *
      * @param  string $title Text to be in the h1
-     * @param  int    $level Error level
      * @return string
      */
-    protected function addTitle(string $title, int $level): string
+    protected function addTitle(string $title, Level $level): string
     {
         $title = htmlspecialchars($title, ENT_NOQUOTES, 'UTF-8');
 
-        return '<h1 style="background: '.$this->logLevels[$level].';color: #ffffff;padding: 5px;" class="monolog-output">'.$title.'</h1>';
+        return '<h1 style="background: '.$this->getLevelColor($level).';color: #ffffff;padding: 5px;" class="monolog-output">'.$title.'</h1>';
     }
 
     /**
@@ -86,7 +87,7 @@ class HtmlFormatter extends NormalizerFormatter
      */
     public function format(LogRecord $record): string
     {
-        $output = $this->addTitle($record->levelName, $record->level);
+        $output = $this->addTitle($record->levelName->value, $record->level);
         $output .= '<table cellspacing="1" width="100%" class="monolog-output">';
 
         $output .= $this->addRow('Message', (string) $record->message);
diff --git a/src/Monolog/Formatter/WildfireFormatter.php b/src/Monolog/Formatter/WildfireFormatter.php
index 0d7f23f0..7badab35 100644
--- a/src/Monolog/Formatter/WildfireFormatter.php
+++ b/src/Monolog/Formatter/WildfireFormatter.php
@@ -11,6 +11,7 @@
 
 namespace Monolog\Formatter;
 
+use Monolog\Level;
 use Monolog\Logger;
 use Monolog\LogRecord;
 
@@ -20,27 +21,9 @@ use Monolog\LogRecord;
  * @author Eric Clemmons (@ericclemmons) <eric@uxdriven.com>
  * @author Christophe Coevoet <stof@notk.org>
  * @author Kirill chEbba Chebunin <iam@chebba.org>
- *
- * @phpstan-import-type Level from \Monolog\Logger
  */
 class WildfireFormatter extends NormalizerFormatter
 {
-    /**
-     * Translates Monolog log levels to Wildfire levels.
-     *
-     * @var array<Level, string>
-     */
-    private $logLevels = [
-        Logger::DEBUG     => 'LOG',
-        Logger::INFO      => 'INFO',
-        Logger::NOTICE    => 'INFO',
-        Logger::WARNING   => 'WARN',
-        Logger::ERROR     => 'ERROR',
-        Logger::CRITICAL  => 'ERROR',
-        Logger::ALERT     => 'ERROR',
-        Logger::EMERGENCY => 'ERROR',
-    ];
-
     /**
      * @param string|null $dateFormat The format of the timestamp: one supported by DateTime::format
      */
@@ -52,6 +35,25 @@ class WildfireFormatter extends NormalizerFormatter
         $this->removeJsonEncodeOption(JSON_UNESCAPED_UNICODE);
     }
 
+    /**
+     * Translates Monolog log levels to Wildfire levels.
+     *
+     * @return 'LOG'|'INFO'|'WARN'|'ERROR'
+     */
+    private function toWildfireLevel(Level $level): string
+    {
+        return match ($level) {
+            Level::Debug     => 'LOG',
+            Level::Info      => 'INFO',
+            Level::Notice    => 'INFO',
+            Level::Warning   => 'WARN',
+            Level::Error     => 'ERROR',
+            Level::Critical  => 'ERROR',
+            Level::Alert     => 'ERROR',
+            Level::Emergency => 'ERROR',
+        };
+    }
+
     /**
      * {@inheritDoc}
      *
@@ -89,7 +91,7 @@ class WildfireFormatter extends NormalizerFormatter
             $label = $record->channel .': '. $record->message;
             $message = $message['context']['table'];
         } else {
-            $type  = $this->logLevels[$record->level];
+            $type  = $this->toWildfireLevel($record->level);
             $label = $record->channel;
         }
 
diff --git a/src/Monolog/Handler/AbstractHandler.php b/src/Monolog/Handler/AbstractHandler.php
index 51f3db53..8d248693 100644
--- a/src/Monolog/Handler/AbstractHandler.php
+++ b/src/Monolog/Handler/AbstractHandler.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Monolog\ResettableInterface;
 use Psr\Log\LogLevel;
@@ -20,27 +22,20 @@ use Monolog\LogRecord;
  * Base Handler class providing basic level/bubble support
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 abstract class AbstractHandler extends Handler implements ResettableInterface
 {
-    /**
-     * @var int
-     * @phpstan-var Level
-     */
-    protected $level = Logger::DEBUG;
+    protected Level $level = Level::Debug;
     /** @var bool */
     protected $bubble = true;
 
     /**
-     * @param int|string $level  The minimum logging level at which this handler will be triggered
-     * @param bool       $bubble Whether the messages that are handled can bubble up the stack or not
+     * @param int|string|Level|LevelName|LogLevel::* $level  The minimum logging level at which this handler will be triggered
+     * @param bool $bubble Whether the messages that are handled can bubble up the stack or not
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function __construct($level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(int|string|Level|LevelName $level = Level::Debug, bool $bubble = true)
     {
         $this->setLevel($level);
         $this->bubble = $bubble;
@@ -51,7 +46,7 @@ abstract class AbstractHandler extends Handler implements ResettableInterface
      */
     public function isHandling(LogRecord $record): bool
     {
-        return $record->level >= $this->level;
+        return $record->level->value >= $this->level->value;
     }
 
     /**
@@ -59,8 +54,10 @@ abstract class AbstractHandler extends Handler implements ResettableInterface
      *
      * @param  Level|LevelName|LogLevel::* $level Level or level name
      * @return self
+     *
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function setLevel($level): self
+    public function setLevel(int|string|Level|LevelName $level): self
     {
         $this->level = Logger::toMonologLevel($level);
 
@@ -69,12 +66,8 @@ abstract class AbstractHandler extends Handler implements ResettableInterface
 
     /**
      * Gets minimum logging level at which this handler will be triggered.
-     *
-     * @return int
-     *
-     * @phpstan-return Level
      */
-    public function getLevel(): int
+    public function getLevel(): Level
     {
         return $this->level;
     }
diff --git a/src/Monolog/Handler/AbstractProcessingHandler.php b/src/Monolog/Handler/AbstractProcessingHandler.php
index 25320053..56a83cc1 100644
--- a/src/Monolog/Handler/AbstractProcessingHandler.php
+++ b/src/Monolog/Handler/AbstractProcessingHandler.php
@@ -20,9 +20,6 @@ use Monolog\LogRecord;
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
  * @author Christophe Coevoet <stof@notk.org>
- *
- * @phpstan-import-type LevelName from \Monolog\Logger
- * @phpstan-import-type Level from \Monolog\Logger
  */
 abstract class AbstractProcessingHandler extends AbstractHandler implements ProcessableHandlerInterface, FormattableHandlerInterface
 {
diff --git a/src/Monolog/Handler/AbstractSyslogHandler.php b/src/Monolog/Handler/AbstractSyslogHandler.php
index 5e5ad1c1..0cba315d 100644
--- a/src/Monolog/Handler/AbstractSyslogHandler.php
+++ b/src/Monolog/Handler/AbstractSyslogHandler.php
@@ -11,14 +11,12 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\LineFormatter;
 
 /**
  * Common syslog functionality
- *
- * @phpstan-import-type Level from \Monolog\Logger
  */
 abstract class AbstractSyslogHandler extends AbstractProcessingHandler
 {
@@ -27,54 +25,55 @@ abstract class AbstractSyslogHandler extends AbstractProcessingHandler
 
     /**
      * Translates Monolog log levels to syslog log priorities.
-     * @var array
-     * @phpstan-var array<Level, int>
      */
-    protected $logLevels = [
-        Logger::DEBUG     => LOG_DEBUG,
-        Logger::INFO      => LOG_INFO,
-        Logger::NOTICE    => LOG_NOTICE,
-        Logger::WARNING   => LOG_WARNING,
-        Logger::ERROR     => LOG_ERR,
-        Logger::CRITICAL  => LOG_CRIT,
-        Logger::ALERT     => LOG_ALERT,
-        Logger::EMERGENCY => LOG_EMERG,
-    ];
+    protected function toSyslogPriority(Level $level): int
+    {
+        return match ($level) {
+            Level::Debug     => \LOG_DEBUG,
+            Level::Info      => \LOG_INFO,
+            Level::Notice    => \LOG_NOTICE,
+            Level::Warning   => \LOG_WARNING,
+            Level::Error     => \LOG_ERR,
+            Level::Critical  => \LOG_CRIT,
+            Level::Alert     => \LOG_ALERT,
+            Level::Emergency => \LOG_EMERG,
+        };
+    }
 
     /**
      * List of valid log facility names.
      * @var array<string, int>
      */
     protected $facilities = [
-        'auth'     => LOG_AUTH,
-        'authpriv' => LOG_AUTHPRIV,
-        'cron'     => LOG_CRON,
-        'daemon'   => LOG_DAEMON,
-        'kern'     => LOG_KERN,
-        'lpr'      => LOG_LPR,
-        'mail'     => LOG_MAIL,
-        'news'     => LOG_NEWS,
-        'syslog'   => LOG_SYSLOG,
-        'user'     => LOG_USER,
-        'uucp'     => LOG_UUCP,
+        'auth'     => \LOG_AUTH,
+        'authpriv' => \LOG_AUTHPRIV,
+        'cron'     => \LOG_CRON,
+        'daemon'   => \LOG_DAEMON,
+        'kern'     => \LOG_KERN,
+        'lpr'      => \LOG_LPR,
+        'mail'     => \LOG_MAIL,
+        'news'     => \LOG_NEWS,
+        'syslog'   => \LOG_SYSLOG,
+        'user'     => \LOG_USER,
+        'uucp'     => \LOG_UUCP,
     ];
 
     /**
      * @param string|int $facility Either one of the names of the keys in $this->facilities, or a LOG_* facility constant
      */
-    public function __construct($facility = LOG_USER, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct($facility = \LOG_USER, $level = Level::Debug, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
 
         if (!defined('PHP_WINDOWS_VERSION_BUILD')) {
-            $this->facilities['local0'] = LOG_LOCAL0;
-            $this->facilities['local1'] = LOG_LOCAL1;
-            $this->facilities['local2'] = LOG_LOCAL2;
-            $this->facilities['local3'] = LOG_LOCAL3;
-            $this->facilities['local4'] = LOG_LOCAL4;
-            $this->facilities['local5'] = LOG_LOCAL5;
-            $this->facilities['local6'] = LOG_LOCAL6;
-            $this->facilities['local7'] = LOG_LOCAL7;
+            $this->facilities['local0'] = \LOG_LOCAL0;
+            $this->facilities['local1'] = \LOG_LOCAL1;
+            $this->facilities['local2'] = \LOG_LOCAL2;
+            $this->facilities['local3'] = \LOG_LOCAL3;
+            $this->facilities['local4'] = \LOG_LOCAL4;
+            $this->facilities['local5'] = \LOG_LOCAL5;
+            $this->facilities['local6'] = \LOG_LOCAL6;
+            $this->facilities['local7'] = \LOG_LOCAL7;
         } else {
             $this->facilities['local0'] = 128; // LOG_LOCAL0
             $this->facilities['local1'] = 136; // LOG_LOCAL1
diff --git a/src/Monolog/Handler/AmqpHandler.php b/src/Monolog/Handler/AmqpHandler.php
index 09c5b3d8..3500732a 100644
--- a/src/Monolog/Handler/AmqpHandler.php
+++ b/src/Monolog/Handler/AmqpHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\JsonFormatter;
 use PhpAmqpLib\Message\AMQPMessage;
@@ -35,7 +35,7 @@ class AmqpHandler extends AbstractProcessingHandler
      * @param AMQPExchange|AMQPChannel $exchange     AMQPExchange (php AMQP ext) or PHP AMQP lib channel, ready for use
      * @param string|null              $exchangeName Optional exchange name, for AMQPChannel (PhpAmqpLib) only
      */
-    public function __construct($exchange, ?string $exchangeName = null, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct($exchange, ?string $exchangeName = null, $level = Level::Debug, bool $bubble = true)
     {
         if ($exchange instanceof AMQPChannel) {
             $this->exchangeName = (string) $exchangeName;
@@ -110,7 +110,7 @@ class AmqpHandler extends AbstractProcessingHandler
      */
     protected function getRoutingKey(LogRecord $record): string
     {
-        $routingKey = sprintf('%s.%s', $record->levelName, $record->channel);
+        $routingKey = sprintf('%s.%s', $record->levelName->value, $record->channel);
 
         return strtolower($routingKey);
     }
diff --git a/src/Monolog/Handler/BufferHandler.php b/src/Monolog/Handler/BufferHandler.php
index 8edf6965..26b3e7c1 100644
--- a/src/Monolog/Handler/BufferHandler.php
+++ b/src/Monolog/Handler/BufferHandler.php
@@ -11,7 +11,8 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\ResettableInterface;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\LogRecord;
@@ -46,7 +47,7 @@ class BufferHandler extends AbstractHandler implements ProcessableHandlerInterfa
      * @param int              $bufferLimit     How many entries should be buffered at most, beyond that the oldest items are removed from the buffer.
      * @param bool             $flushOnOverflow If true, the buffer is flushed when the max size has been reached, by default oldest entries are discarded
      */
-    public function __construct(HandlerInterface $handler, int $bufferLimit = 0, $level = Logger::DEBUG, bool $bubble = true, bool $flushOnOverflow = false)
+    public function __construct(HandlerInterface $handler, int $bufferLimit = 0, int|string|Level|LevelName $level = Level::Debug, bool $bubble = true, bool $flushOnOverflow = false)
     {
         parent::__construct($level, $bubble);
         $this->handler = $handler;
@@ -59,7 +60,7 @@ class BufferHandler extends AbstractHandler implements ProcessableHandlerInterfa
      */
     public function handle(LogRecord $record): bool
     {
-        if ($record->level < $this->level) {
+        if ($record->level->isLowerThan($this->level)) {
             return false;
         }
 
diff --git a/src/Monolog/Handler/ChromePHPHandler.php b/src/Monolog/Handler/ChromePHPHandler.php
index 345ba90c..b08f004c 100644
--- a/src/Monolog/Handler/ChromePHPHandler.php
+++ b/src/Monolog/Handler/ChromePHPHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\ChromePHPFormatter;
 use Monolog\Formatter\FormatterInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 use Monolog\DateTimeImmutable;
@@ -66,7 +66,7 @@ class ChromePHPHandler extends AbstractProcessingHandler
     /** @var bool */
     protected static $sendHeaders = true;
 
-    public function __construct($level = Logger::DEBUG, bool $bubble = true)
+    public function __construct($level = Level::Debug, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
         if (!function_exists('json_encode')) {
@@ -155,7 +155,7 @@ class ChromePHPHandler extends AbstractProcessingHandler
 
             $record = new LogRecord(
                 message: 'Incomplete logs, chrome header size limit reached',
-                level: Logger::WARNING,
+                level: Level::Warning,
                 channel: 'monolog',
                 datetime: new DateTimeImmutable(true),
             );
diff --git a/src/Monolog/Handler/CouchDBHandler.php b/src/Monolog/Handler/CouchDBHandler.php
index abdce0b5..0369ee89 100644
--- a/src/Monolog/Handler/CouchDBHandler.php
+++ b/src/Monolog/Handler/CouchDBHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\JsonFormatter;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -29,7 +29,7 @@ class CouchDBHandler extends AbstractProcessingHandler
     /**
      * @param mixed[] $options
      */
-    public function __construct(array $options = [], $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(array $options = [], $level = Level::Debug, bool $bubble = true)
     {
         $this->options = array_merge([
             'host'     => 'localhost',
diff --git a/src/Monolog/Handler/CubeHandler.php b/src/Monolog/Handler/CubeHandler.php
index 40a16f5c..d013671d 100644
--- a/src/Monolog/Handler/CubeHandler.php
+++ b/src/Monolog/Handler/CubeHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -43,7 +43,7 @@ class CubeHandler extends AbstractProcessingHandler
      *                                   A valid url must consist of three parts : protocol://host:port
      *                                   Only valid protocols used by Cube are http and udp
      */
-    public function __construct(string $url, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(string $url, $level = Level::Debug, bool $bubble = true)
     {
         $urlInfo = parse_url($url);
 
diff --git a/src/Monolog/Handler/DeduplicationHandler.php b/src/Monolog/Handler/DeduplicationHandler.php
index f9d80f2d..f1f01e3b 100644
--- a/src/Monolog/Handler/DeduplicationHandler.php
+++ b/src/Monolog/Handler/DeduplicationHandler.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Psr\Log\LogLevel;
 use Monolog\LogRecord;
@@ -34,8 +36,6 @@ use Monolog\LogRecord;
  * same way.
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- * @phpstan-import-type LevelName from \Monolog\Logger
- * @phpstan-import-type Level from \Monolog\Logger
  */
 class DeduplicationHandler extends BufferHandler
 {
@@ -62,15 +62,15 @@ class DeduplicationHandler extends BufferHandler
     /**
      * @param HandlerInterface $handler            Handler.
      * @param string           $deduplicationStore The file/path where the deduplication log should be kept
-     * @param string|int       $deduplicationLevel The minimum logging level for log records to be looked at for deduplication purposes
+     * @param int|string|Level|LevelName|LogLevel::* $deduplicationLevel The minimum logging level for log records to be looked at for deduplication purposes
      * @param int              $time               The period (in seconds) during which duplicate entries should be suppressed after a given log is sent through
      * @param bool             $bubble             Whether the messages that are handled can bubble up the stack or not
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $deduplicationLevel
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $deduplicationLevel
      */
-    public function __construct(HandlerInterface $handler, ?string $deduplicationStore = null, $deduplicationLevel = Logger::ERROR, int $time = 60, bool $bubble = true)
+    public function __construct(HandlerInterface $handler, ?string $deduplicationStore = null, int|string|Level|LevelName $deduplicationLevel = Level::Error, int $time = 60, bool $bubble = true)
     {
-        parent::__construct($handler, 0, Logger::DEBUG, $bubble, false);
+        parent::__construct($handler, 0, Level::Debug, $bubble, false);
 
         $this->deduplicationStore = $deduplicationStore === null ? sys_get_temp_dir() . '/monolog-dedup-' . substr(md5(__FILE__), 0, 20) .'.log' : $deduplicationStore;
         $this->deduplicationLevel = Logger::toMonologLevel($deduplicationLevel);
@@ -86,7 +86,7 @@ class DeduplicationHandler extends BufferHandler
         $passthru = null;
 
         foreach ($this->buffer as $record) {
-            if ($record->level >= $this->deduplicationLevel) {
+            if ($record->level->value >= $this->deduplicationLevel->value) {
                 $passthru = $passthru || !$this->isDuplicate($record);
                 if ($passthru) {
                     $this->appendRecord($record);
@@ -124,7 +124,7 @@ class DeduplicationHandler extends BufferHandler
         for ($i = count($store) - 1; $i >= 0; $i--) {
             list($timestamp, $level, $message) = explode(':', $store[$i], 3);
 
-            if ($level === $record->levelName && $message === $expectedMessage && $timestamp > $timestampValidity) {
+            if ($level === $record->levelName->value && $message === $expectedMessage && $timestamp > $timestampValidity) {
                 return true;
             }
 
@@ -174,6 +174,6 @@ class DeduplicationHandler extends BufferHandler
 
     private function appendRecord(LogRecord $record): void
     {
-        file_put_contents($this->deduplicationStore, $record->datetime->getTimestamp() . ':' . $record->levelName . ':' . preg_replace('{[\r\n].*}', '', $record->message) . "\n", FILE_APPEND);
+        file_put_contents($this->deduplicationStore, $record->datetime->getTimestamp() . ':' . $record->levelName->value . ':' . preg_replace('{[\r\n].*}', '', $record->message) . "\n", FILE_APPEND);
     }
 }
diff --git a/src/Monolog/Handler/DoctrineCouchDBHandler.php b/src/Monolog/Handler/DoctrineCouchDBHandler.php
index 9b3426f8..0ce3ae9f 100644
--- a/src/Monolog/Handler/DoctrineCouchDBHandler.php
+++ b/src/Monolog/Handler/DoctrineCouchDBHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\NormalizerFormatter;
 use Monolog\Formatter\FormatterInterface;
 use Doctrine\CouchDB\CouchDBClient;
@@ -27,7 +27,7 @@ class DoctrineCouchDBHandler extends AbstractProcessingHandler
     /** @var CouchDBClient */
     private $client;
 
-    public function __construct(CouchDBClient $client, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(CouchDBClient $client, $level = Level::Debug, bool $bubble = true)
     {
         $this->client = $client;
         parent::__construct($level, $bubble);
diff --git a/src/Monolog/Handler/DynamoDbHandler.php b/src/Monolog/Handler/DynamoDbHandler.php
index 175ab71b..c9c469f0 100644
--- a/src/Monolog/Handler/DynamoDbHandler.php
+++ b/src/Monolog/Handler/DynamoDbHandler.php
@@ -16,7 +16,7 @@ use Aws\DynamoDb\DynamoDbClient;
 use Monolog\Formatter\FormatterInterface;
 use Aws\DynamoDb\Marshaler;
 use Monolog\Formatter\ScalarFormatter;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -44,7 +44,7 @@ class DynamoDbHandler extends AbstractProcessingHandler
      */
     protected $marshaler;
 
-    public function __construct(DynamoDbClient $client, string $table, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(DynamoDbClient $client, string $table, $level = Level::Debug, bool $bubble = true)
     {
         $this->marshaler = new Marshaler;
 
diff --git a/src/Monolog/Handler/ElasticaHandler.php b/src/Monolog/Handler/ElasticaHandler.php
index 838d9d2b..29dc74b1 100644
--- a/src/Monolog/Handler/ElasticaHandler.php
+++ b/src/Monolog/Handler/ElasticaHandler.php
@@ -14,7 +14,7 @@ namespace Monolog\Handler;
 use Elastica\Document;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\ElasticaFormatter;
-use Monolog\Logger;
+use Monolog\Level;
 use Elastica\Client;
 use Elastica\Exception\ExceptionInterface;
 use Monolog\LogRecord;
@@ -51,7 +51,7 @@ class ElasticaHandler extends AbstractProcessingHandler
      * @param Client  $client  Elastica Client object
      * @param mixed[] $options Handler configuration
      */
-    public function __construct(Client $client, array $options = [], $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(Client $client, array $options = [], $level = Level::Debug, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
         $this->client = $client;
diff --git a/src/Monolog/Handler/ElasticsearchHandler.php b/src/Monolog/Handler/ElasticsearchHandler.php
index 0694bcb0..a669dde7 100644
--- a/src/Monolog/Handler/ElasticsearchHandler.php
+++ b/src/Monolog/Handler/ElasticsearchHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Throwable;
 use RuntimeException;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\ElasticsearchFormatter;
 use InvalidArgumentException;
@@ -58,7 +58,7 @@ class ElasticsearchHandler extends AbstractProcessingHandler
      * @param Client  $client  Elasticsearch Client object
      * @param mixed[] $options Handler configuration
      */
-    public function __construct(Client $client, array $options = [], $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(Client $client, array $options = [], $level = Level::Debug, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
         $this->client = $client;
diff --git a/src/Monolog/Handler/ErrorLogHandler.php b/src/Monolog/Handler/ErrorLogHandler.php
index c0f62298..a80b63ad 100644
--- a/src/Monolog/Handler/ErrorLogHandler.php
+++ b/src/Monolog/Handler/ErrorLogHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\LineFormatter;
 use Monolog\Formatter\FormatterInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -36,7 +36,7 @@ class ErrorLogHandler extends AbstractProcessingHandler
      * @param int  $messageType    Says where the error should go.
      * @param bool $expandNewlines If set to true, newlines in the message will be expanded to be take multiple log entries
      */
-    public function __construct(int $messageType = self::OPERATING_SYSTEM, $level = Logger::DEBUG, bool $bubble = true, bool $expandNewlines = false)
+    public function __construct(int $messageType = self::OPERATING_SYSTEM, $level = Level::Debug, bool $bubble = true, bool $expandNewlines = false)
     {
         parent::__construct($level, $bubble);
 
diff --git a/src/Monolog/Handler/FilterHandler.php b/src/Monolog/Handler/FilterHandler.php
index d6703fe1..b5dec938 100644
--- a/src/Monolog/Handler/FilterHandler.php
+++ b/src/Monolog/Handler/FilterHandler.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Monolog\ResettableInterface;
 use Monolog\Formatter\FormatterInterface;
@@ -24,8 +26,6 @@ use Monolog\LogRecord;
  *
  * @author Hennadiy Verkh
  * @author Jordi Boggiano <j.boggiano@seld.be>
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class FilterHandler extends Handler implements ProcessableHandlerInterface, ResettableInterface, FormattableHandlerInterface
 {
@@ -42,10 +42,10 @@ class FilterHandler extends Handler implements ProcessableHandlerInterface, Rese
     /**
      * Minimum level for logs that are passed to handler
      *
-     * @var int[]
-     * @phpstan-var array<Level, int>
+     * @var bool[] Map of Level value => true
+     * @phpstan-var array<value-of<Level::VALUES>, true>
      */
-    protected $acceptedLevels;
+    protected array $acceptedLevels;
 
     /**
      * Whether the messages that are handled can bubble up the stack or not
@@ -58,14 +58,14 @@ class FilterHandler extends Handler implements ProcessableHandlerInterface, Rese
      * @phpstan-param (callable(LogRecord|null, HandlerInterface): HandlerInterface)|HandlerInterface $handler
      *
      * @param callable|HandlerInterface $handler        Handler or factory callable($record|null, $filterHandler).
-     * @param int|array                 $minLevelOrList A list of levels to accept or a minimum level if maxLevel is provided
-     * @param int|string                $maxLevel       Maximum level to accept, only used if $minLevelOrList is not an array
+     * @param int|string|Level|LevelName|array<int|string|Level|LevelName|LogLevel::*> $minLevelOrList A list of levels to accept or a minimum level if maxLevel is provided
+     * @param int|string|Level|LevelName|LogLevel::* $maxLevel Maximum level to accept, only used if $minLevelOrList is not an array
      * @param bool                      $bubble         Whether the messages that are handled can bubble up the stack or not
      *
-     * @phpstan-param Level|LevelName|LogLevel::*|array<Level|LevelName|LogLevel::*> $minLevelOrList
-     * @phpstan-param Level|LevelName|LogLevel::* $maxLevel
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::*|array<value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::*> $minLevelOrList
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $maxLevel
      */
-    public function __construct($handler, $minLevelOrList = Logger::DEBUG, $maxLevel = Logger::EMERGENCY, bool $bubble = true)
+    public function __construct($handler, int|string|Level|LevelName|array $minLevelOrList = Level::Debug, int|string|Level|LevelName $maxLevel = Level::Emergency, bool $bubble = true)
     {
         $this->handler  = $handler;
         $this->bubble   = $bubble;
@@ -77,32 +77,33 @@ class FilterHandler extends Handler implements ProcessableHandlerInterface, Rese
     }
 
     /**
-     * @phpstan-return array<int, Level>
+     * @phpstan-return list<Level> List of levels
      */
     public function getAcceptedLevels(): array
     {
-        return array_flip($this->acceptedLevels);
+        return array_map(fn(int $level) => Level::from($level), array_keys($this->acceptedLevels));
     }
 
     /**
-     * @param int|string|array $minLevelOrList A list of levels to accept or a minimum level or level name if maxLevel is provided
-     * @param int|string       $maxLevel       Maximum level or level name to accept, only used if $minLevelOrList is not an array
+     * @param int|string|Level|LevelName|LogLevel::*|array<int|string|Level|LevelName|LogLevel::*> $minLevelOrList A list of levels to accept or a minimum level or level name if maxLevel is provided
+     * @param int|string|Level|LevelName|LogLevel::* $maxLevel Maximum level or level name to accept, only used if $minLevelOrList is not an array
      *
-     * @phpstan-param Level|LevelName|LogLevel::*|array<Level|LevelName|LogLevel::*> $minLevelOrList
-     * @phpstan-param Level|LevelName|LogLevel::*                                    $maxLevel
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::*|array<value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::*> $minLevelOrList
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $maxLevel
      */
-    public function setAcceptedLevels($minLevelOrList = Logger::DEBUG, $maxLevel = Logger::EMERGENCY): self
+    public function setAcceptedLevels(int|string|Level|LevelName|array $minLevelOrList = Level::Debug, int|string|Level|LevelName $maxLevel = Level::Emergency): self
     {
         if (is_array($minLevelOrList)) {
-            $acceptedLevels = array_map('Monolog\Logger::toMonologLevel', $minLevelOrList);
+            $acceptedLevels = array_map(Logger::toMonologLevel(...), $minLevelOrList);
         } else {
             $minLevelOrList = Logger::toMonologLevel($minLevelOrList);
             $maxLevel = Logger::toMonologLevel($maxLevel);
-            $acceptedLevels = array_values(array_filter(Logger::getLevels(), function ($level) use ($minLevelOrList, $maxLevel) {
-                return $level >= $minLevelOrList && $level <= $maxLevel;
-            }));
+            $acceptedLevels = array_values(array_filter(Level::cases(), fn (Level $level) => $level->value >= $minLevelOrList->value && $level->value <= $maxLevel->value));
+        }
+        $this->acceptedLevels = [];
+        foreach ($acceptedLevels as $level) {
+            $this->acceptedLevels[$level->value] = true;
         }
-        $this->acceptedLevels = array_flip($acceptedLevels);
 
         return $this;
     }
@@ -112,7 +113,7 @@ class FilterHandler extends Handler implements ProcessableHandlerInterface, Rese
      */
     public function isHandling(LogRecord $record): bool
     {
-        return isset($this->acceptedLevels[$record->level]);
+        return isset($this->acceptedLevels[$record->level->value]);
     }
 
     /**
diff --git a/src/Monolog/Handler/FingersCrossed/ChannelLevelActivationStrategy.php b/src/Monolog/Handler/FingersCrossed/ChannelLevelActivationStrategy.php
index ca34b3b7..4da75dff 100644
--- a/src/Monolog/Handler/FingersCrossed/ChannelLevelActivationStrategy.php
+++ b/src/Monolog/Handler/FingersCrossed/ChannelLevelActivationStrategy.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Handler\FingersCrossed;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Psr\Log\LogLevel;
 use Monolog\LogRecord;
@@ -24,50 +26,45 @@ use Monolog\LogRecord;
  *
  * <code>
  *   $activationStrategy = new ChannelLevelActivationStrategy(
- *       Logger::CRITICAL,
+ *       Level::Critical,
  *       array(
- *           'request' => Logger::ALERT,
- *           'sensitive' => Logger::ERROR,
+ *           'request' => Level::Alert,
+ *           'sensitive' => Level::Error,
  *       )
  *   );
  *   $handler = new FingersCrossedHandler(new StreamHandler('php://stderr'), $activationStrategy);
  * </code>
  *
  * @author Mike Meessen <netmikey@gmail.com>
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class ChannelLevelActivationStrategy implements ActivationStrategyInterface
 {
-    /**
-     * @var Level
-     */
-    private $defaultActionLevel;
+    private Level $defaultActionLevel;
 
     /**
      * @var array<string, Level>
      */
-    private $channelToActionLevel;
+    private array $channelToActionLevel;
 
     /**
-     * @param int|string         $defaultActionLevel   The default action level to be used if the record's category doesn't match any
-     * @param array<string, int> $channelToActionLevel An array that maps channel names to action levels.
+     * @param int|string|Level|LevelName|LogLevel::* $defaultActionLevel   The default action level to be used if the record's category doesn't match any
+     * @param array<string, int|string|Level|LevelName|LogLevel::*> $channelToActionLevel An array that maps channel names to action levels.
      *
-     * @phpstan-param array<string, Level>        $channelToActionLevel
-     * @phpstan-param Level|LevelName|LogLevel::* $defaultActionLevel
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $defaultActionLevel
+     * @phpstan-param array<string, value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::*> $channelToActionLevel
      */
-    public function __construct($defaultActionLevel, array $channelToActionLevel = [])
+    public function __construct(int|string|Level|LevelName $defaultActionLevel, array $channelToActionLevel = [])
     {
         $this->defaultActionLevel = Logger::toMonologLevel($defaultActionLevel);
-        $this->channelToActionLevel = array_map('Monolog\Logger::toMonologLevel', $channelToActionLevel);
+        $this->channelToActionLevel = array_map(Logger::toMonologLevel(...), $channelToActionLevel);
     }
 
     public function isHandlerActivated(LogRecord $record): bool
     {
         if (isset($this->channelToActionLevel[$record->channel])) {
-            return $record->level >= $this->channelToActionLevel[$record->channel];
+            return $record->level->value >= $this->channelToActionLevel[$record->channel]->value;
         }
 
-        return $record->level >= $this->defaultActionLevel;
+        return $record->level->value >= $this->defaultActionLevel->value;
     }
 }
diff --git a/src/Monolog/Handler/FingersCrossed/ErrorLevelActivationStrategy.php b/src/Monolog/Handler/FingersCrossed/ErrorLevelActivationStrategy.php
index ba98f505..2b4e9ec7 100644
--- a/src/Monolog/Handler/FingersCrossed/ErrorLevelActivationStrategy.php
+++ b/src/Monolog/Handler/FingersCrossed/ErrorLevelActivationStrategy.php
@@ -11,37 +11,33 @@
 
 namespace Monolog\Handler\FingersCrossed;
 
+use Monolog\Level;
+use Monolog\LevelName;
+use Monolog\LogRecord;
 use Monolog\Logger;
 use Psr\Log\LogLevel;
-use Monolog\LogRecord;
 
 /**
  * Error level based activation strategy.
  *
  * @author Johannes M. Schmitt <schmittjoh@gmail.com>
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class ErrorLevelActivationStrategy implements ActivationStrategyInterface
 {
-    /**
-     * @var Level
-     */
-    private $actionLevel;
+    private Level $actionLevel;
 
     /**
-     * @param int|string $actionLevel Level or name or value
+     * @param int|string|Level|LevelName $actionLevel Level or name or value
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $actionLevel
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $actionLevel
      */
-    public function __construct($actionLevel)
+    public function __construct(int|string|Level|LevelName $actionLevel)
     {
         $this->actionLevel = Logger::toMonologLevel($actionLevel);
     }
 
     public function isHandlerActivated(LogRecord $record): bool
     {
-        return $record->level >= $this->actionLevel;
+        return $record->level->value >= $this->actionLevel->value;
     }
 }
diff --git a/src/Monolog/Handler/FingersCrossedHandler.php b/src/Monolog/Handler/FingersCrossedHandler.php
index 872b9a18..fab57656 100644
--- a/src/Monolog/Handler/FingersCrossedHandler.php
+++ b/src/Monolog/Handler/FingersCrossedHandler.php
@@ -13,6 +13,8 @@ namespace Monolog\Handler;
 
 use Monolog\Handler\FingersCrossed\ErrorLevelActivationStrategy;
 use Monolog\Handler\FingersCrossed\ActivationStrategyInterface;
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Monolog\ResettableInterface;
 use Monolog\Formatter\FormatterInterface;
@@ -34,8 +36,6 @@ use Monolog\LogRecord;
  * Monolog\Handler\FingersCrossed\ namespace.
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class FingersCrossedHandler extends Handler implements ProcessableHandlerInterface, ResettableInterface, FormattableHandlerInterface
 {
@@ -56,11 +56,7 @@ class FingersCrossedHandler extends Handler implements ProcessableHandlerInterfa
     protected $buffer = [];
     /** @var bool */
     protected $stopBuffering;
-    /**
-     * @var ?int
-     * @phpstan-var ?Level
-     */
-    protected $passthruLevel;
+    protected Level|null $passthruLevel = null;
     /** @var bool */
     protected $bubble;
 
@@ -68,19 +64,19 @@ class FingersCrossedHandler extends Handler implements ProcessableHandlerInterfa
      * @phpstan-param (callable(LogRecord|null, HandlerInterface): HandlerInterface)|HandlerInterface $handler
      *
      * @param callable|HandlerInterface              $handler            Handler or factory callable($record|null, $fingersCrossedHandler).
-     * @param int|string|ActivationStrategyInterface $activationStrategy Strategy which determines when this handler takes action, or a level name/value at which the handler is activated
+     * @param int|string|Level|LevelName|LogLevel::* $activationStrategy Strategy which determines when this handler takes action, or a level name/value at which the handler is activated
      * @param int                                    $bufferSize         How many entries should be buffered at most, beyond that the oldest items are removed from the buffer.
      * @param bool                                   $bubble             Whether the messages that are handled can bubble up the stack or not
      * @param bool                                   $stopBuffering      Whether the handler should stop buffering after being triggered (default true)
-     * @param int|string                             $passthruLevel      Minimum level to always flush to handler on close, even if strategy not triggered
+     * @param int|string|Level|LevelName|LogLevel::* $passthruLevel      Minimum level to always flush to handler on close, even if strategy not triggered
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $passthruLevel
-     * @phpstan-param Level|LevelName|LogLevel::*|ActivationStrategyInterface $activationStrategy
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::*|ActivationStrategyInterface $activationStrategy
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $passthruLevel
      */
-    public function __construct($handler, $activationStrategy = null, int $bufferSize = 0, bool $bubble = true, bool $stopBuffering = true, $passthruLevel = null)
+    public function __construct($handler, int|string|Level|LevelName|ActivationStrategyInterface $activationStrategy = null, int $bufferSize = 0, bool $bubble = true, bool $stopBuffering = true, int|string|Level|LevelName $passthruLevel = null)
     {
         if (null === $activationStrategy) {
-            $activationStrategy = new ErrorLevelActivationStrategy(Logger::WARNING);
+            $activationStrategy = new ErrorLevelActivationStrategy(Level::Warning);
         }
 
         // convert simple int activationStrategy to an object
diff --git a/src/Monolog/Handler/FleepHookHandler.php b/src/Monolog/Handler/FleepHookHandler.php
index 82614cb8..9f84c5bb 100644
--- a/src/Monolog/Handler/FleepHookHandler.php
+++ b/src/Monolog/Handler/FleepHookHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\LineFormatter;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -46,7 +46,7 @@ class FleepHookHandler extends SocketHandler
      */
     public function __construct(
         string $token,
-        $level = Logger::DEBUG,
+        $level = Level::Debug,
         bool $bubble = true,
         bool $persistent = false,
         float $timeout = 0.0,
diff --git a/src/Monolog/Handler/FlowdockHandler.php b/src/Monolog/Handler/FlowdockHandler.php
index f15857ed..dd3e6132 100644
--- a/src/Monolog/Handler/FlowdockHandler.php
+++ b/src/Monolog/Handler/FlowdockHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\Formatter\FlowdockFormatter;
 use Monolog\Formatter\FormatterInterface;
@@ -40,7 +40,7 @@ class FlowdockHandler extends SocketHandler
      */
     public function __construct(
         string $apiToken,
-        $level = Logger::DEBUG,
+        $level = Level::Debug,
         bool $bubble = true,
         bool $persistent = false,
         float $timeout = 0.0,
diff --git a/src/Monolog/Handler/GelfHandler.php b/src/Monolog/Handler/GelfHandler.php
index b29049c4..1b53dbda 100644
--- a/src/Monolog/Handler/GelfHandler.php
+++ b/src/Monolog/Handler/GelfHandler.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Gelf\PublisherInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\GelfMessageFormatter;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\LogRecord;
@@ -33,7 +33,7 @@ class GelfHandler extends AbstractProcessingHandler
     /**
      * @param PublisherInterface $publisher a gelf publisher object
      */
-    public function __construct(PublisherInterface $publisher, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(PublisherInterface $publisher, $level = Level::Debug, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
 
diff --git a/src/Monolog/Handler/HandlerInterface.php b/src/Monolog/Handler/HandlerInterface.php
index c63ecbbf..53bf28bf 100644
--- a/src/Monolog/Handler/HandlerInterface.php
+++ b/src/Monolog/Handler/HandlerInterface.php
@@ -17,8 +17,6 @@ use Monolog\LogRecord;
  * Interface that all Monolog Handlers must implement
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- *
- * @phpstan-import-type Level from \Monolog\Logger
  */
 interface HandlerInterface
 {
diff --git a/src/Monolog/Handler/IFTTTHandler.php b/src/Monolog/Handler/IFTTTHandler.php
index 4eaa1c95..da50bdd5 100644
--- a/src/Monolog/Handler/IFTTTHandler.php
+++ b/src/Monolog/Handler/IFTTTHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -37,7 +37,7 @@ class IFTTTHandler extends AbstractProcessingHandler
      * @param string $eventName The name of the IFTTT Maker event that should be triggered
      * @param string $secretKey A valid IFTTT secret key
      */
-    public function __construct(string $eventName, string $secretKey, $level = Logger::ERROR, bool $bubble = true)
+    public function __construct(string $eventName, string $secretKey, $level = Level::Error, bool $bubble = true)
     {
         if (!extension_loaded('curl')) {
             throw new MissingExtensionException('The curl extension is needed to use the IFTTTHandler');
diff --git a/src/Monolog/Handler/InsightOpsHandler.php b/src/Monolog/Handler/InsightOpsHandler.php
index 0223d5bb..f6632187 100644
--- a/src/Monolog/Handler/InsightOpsHandler.php
+++ b/src/Monolog/Handler/InsightOpsHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -38,7 +38,7 @@ class InsightOpsHandler extends SocketHandler
         string $token,
         string $region = 'us',
         bool $useSSL = true,
-        $level = Logger::DEBUG,
+        $level = Level::Debug,
         bool $bubble = true,
         bool $persistent = false,
         float $timeout = 0.0,
diff --git a/src/Monolog/Handler/LogEntriesHandler.php b/src/Monolog/Handler/LogEntriesHandler.php
index 8fe5d869..ffa2b0a9 100644
--- a/src/Monolog/Handler/LogEntriesHandler.php
+++ b/src/Monolog/Handler/LogEntriesHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -34,7 +34,7 @@ class LogEntriesHandler extends SocketHandler
     public function __construct(
         string $token,
         bool $useSSL = true,
-        $level = Logger::DEBUG,
+        $level = Level::Debug,
         bool $bubble = true,
         string $host = 'data.logentries.com',
         bool $persistent = false,
diff --git a/src/Monolog/Handler/LogglyHandler.php b/src/Monolog/Handler/LogglyHandler.php
index ef74ee16..07cad391 100644
--- a/src/Monolog/Handler/LogglyHandler.php
+++ b/src/Monolog/Handler/LogglyHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\LogglyFormatter;
 use function array_key_exists;
@@ -49,7 +49,7 @@ class LogglyHandler extends AbstractProcessingHandler
      *
      * @throws MissingExtensionException If the curl extension is missing
      */
-    public function __construct(string $token, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(string $token, $level = Level::Debug, bool $bubble = true)
     {
         if (!extension_loaded('curl')) {
             throw new MissingExtensionException('The curl extension is needed to use the LogglyHandler');
diff --git a/src/Monolog/Handler/LogmaticHandler.php b/src/Monolog/Handler/LogmaticHandler.php
index b2799c2d..b82bfbf1 100644
--- a/src/Monolog/Handler/LogmaticHandler.php
+++ b/src/Monolog/Handler/LogmaticHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\LogmaticFormatter;
 use Monolog\LogRecord;
@@ -49,7 +49,7 @@ class LogmaticHandler extends SocketHandler
         string $hostname = '',
         string $appname = '',
         bool $useSSL = true,
-        $level = Logger::DEBUG,
+        $level = Level::Debug,
         bool $bubble = true,
         bool $persistent = false,
         float $timeout = 0.0,
diff --git a/src/Monolog/Handler/MailHandler.php b/src/Monolog/Handler/MailHandler.php
index bfbe98fe..decd260c 100644
--- a/src/Monolog/Handler/MailHandler.php
+++ b/src/Monolog/Handler/MailHandler.php
@@ -30,7 +30,7 @@ abstract class MailHandler extends AbstractProcessingHandler
         $messages = [];
 
         foreach ($records as $record) {
-            if ($record->level < $this->level) {
+            if ($record->level->isLowerThan($this->level)) {
                 continue;
             }
 
@@ -68,7 +68,7 @@ abstract class MailHandler extends AbstractProcessingHandler
     {
         $highestRecord = null;
         foreach ($records as $record) {
-            if ($highestRecord === null || $highestRecord['level'] < $record->level) {
+            if ($highestRecord === null || $record->level->isHigherThan($highestRecord->level)) {
                 $highestRecord = $record;
             }
         }
diff --git a/src/Monolog/Handler/MandrillHandler.php b/src/Monolog/Handler/MandrillHandler.php
index 9fe10547..07f85bbc 100644
--- a/src/Monolog/Handler/MandrillHandler.php
+++ b/src/Monolog/Handler/MandrillHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Swift;
 use Swift_Message;
 
@@ -33,7 +33,7 @@ class MandrillHandler extends MailHandler
      * @param string                 $apiKey  A valid Mandrill API key
      * @param callable|Swift_Message $message An example message for real messages, only the body will be replaced
      */
-    public function __construct(string $apiKey, $message, $level = Logger::ERROR, bool $bubble = true)
+    public function __construct(string $apiKey, $message, $level = Level::Error, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
 
diff --git a/src/Monolog/Handler/MongoDBHandler.php b/src/Monolog/Handler/MongoDBHandler.php
index 50aaa1e6..d8248f99 100644
--- a/src/Monolog/Handler/MongoDBHandler.php
+++ b/src/Monolog/Handler/MongoDBHandler.php
@@ -14,7 +14,7 @@ namespace Monolog\Handler;
 use MongoDB\Driver\BulkWrite;
 use MongoDB\Driver\Manager;
 use MongoDB\Client;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\MongoDBFormatter;
 use Monolog\LogRecord;
@@ -47,7 +47,7 @@ class MongoDBHandler extends AbstractProcessingHandler
      * @param string         $database   Database name
      * @param string         $collection Collection name
      */
-    public function __construct($mongodb, string $database, string $collection, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct($mongodb, string $database, string $collection, $level = Level::Debug, bool $bubble = true)
     {
         if (!($mongodb instanceof Client || $mongodb instanceof Manager)) {
             throw new \InvalidArgumentException('MongoDB\Client or MongoDB\Driver\Manager instance required');
diff --git a/src/Monolog/Handler/NativeMailerHandler.php b/src/Monolog/Handler/NativeMailerHandler.php
index 0c0a3bdb..6aad468a 100644
--- a/src/Monolog/Handler/NativeMailerHandler.php
+++ b/src/Monolog/Handler/NativeMailerHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\LineFormatter;
 
 /**
@@ -70,7 +70,7 @@ class NativeMailerHandler extends MailHandler
      * @param string          $from           The sender of the mail
      * @param int             $maxColumnWidth The maximum column width that the message lines will have
      */
-    public function __construct($to, string $subject, string $from, $level = Logger::ERROR, bool $bubble = true, int $maxColumnWidth = 70)
+    public function __construct($to, string $subject, string $from, $level = Level::Error, bool $bubble = true, int $maxColumnWidth = 70)
     {
         parent::__construct($level, $bubble);
         $this->to = (array) $to;
diff --git a/src/Monolog/Handler/NewRelicHandler.php b/src/Monolog/Handler/NewRelicHandler.php
index 113aaa49..3b3ae758 100644
--- a/src/Monolog/Handler/NewRelicHandler.php
+++ b/src/Monolog/Handler/NewRelicHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\Formatter\NormalizerFormatter;
 use Monolog\Formatter\FormatterInterface;
@@ -58,7 +58,7 @@ class NewRelicHandler extends AbstractProcessingHandler
      * @param string|null $transactionName
      */
     public function __construct(
-        $level = Logger::ERROR,
+        $level = Level::Error,
         bool $bubble = true,
         ?string $appName = null,
         bool $explodeArrays = false,
diff --git a/src/Monolog/Handler/NullHandler.php b/src/Monolog/Handler/NullHandler.php
index 99c1e659..923d5928 100644
--- a/src/Monolog/Handler/NullHandler.php
+++ b/src/Monolog/Handler/NullHandler.php
@@ -11,8 +11,10 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
+use Monolog\LevelName;
 use Psr\Log\LogLevel;
+use Monolog\Logger;
 use Monolog\LogRecord;
 
 /**
@@ -22,23 +24,17 @@ use Monolog\LogRecord;
  * to put on top of an existing stack to override it temporarily.
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class NullHandler extends Handler
 {
-    /**
-     * @var int
-     */
-    private $level;
+    private Level $level;
 
     /**
-     * @param string|int $level The minimum logging level at which this handler will be triggered
+     * @param string|int|Level|LevelName $level The minimum logging level at which this handler will be triggered
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function __construct($level = Logger::DEBUG)
+    public function __construct(string|int|Level|LevelName $level = Level::Debug)
     {
         $this->level = Logger::toMonologLevel($level);
     }
@@ -48,7 +44,7 @@ class NullHandler extends Handler
      */
     public function isHandling(LogRecord $record): bool
     {
-        return $record->level >= $this->level;
+        return $record->level->value >= $this->level->value;
     }
 
     /**
@@ -56,6 +52,6 @@ class NullHandler extends Handler
      */
     public function handle(LogRecord $record): bool
     {
-        return $record->level >= $this->level;
+        return $record->level->value >= $this->level->value;
     }
 }
diff --git a/src/Monolog/Handler/OverflowHandler.php b/src/Monolog/Handler/OverflowHandler.php
index af33424f..d1f42781 100644
--- a/src/Monolog/Handler/OverflowHandler.php
+++ b/src/Monolog/Handler/OverflowHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\LogRecord;
 
@@ -28,7 +28,7 @@ use Monolog\LogRecord;
  *   $handler = new SomeHandler(...)
  *
  *   // Pass all warnings to the handler when more than 10 & all error messages when more then 5
- *   $overflow = new OverflowHandler($handler, [Logger::WARNING => 10, Logger::ERROR => 5]);
+ *   $overflow = new OverflowHandler($handler, [Level::Warning->value => 10, Level::Error->value => 5]);
  *
  *   $log->pushHandler($overflow);
  *```
@@ -40,17 +40,8 @@ class OverflowHandler extends AbstractHandler implements FormattableHandlerInter
     /** @var HandlerInterface */
     private $handler;
 
-    /** @var int[] */
-    private $thresholdMap = [
-        Logger::DEBUG => 0,
-        Logger::INFO => 0,
-        Logger::NOTICE => 0,
-        Logger::WARNING => 0,
-        Logger::ERROR => 0,
-        Logger::CRITICAL => 0,
-        Logger::ALERT => 0,
-        Logger::EMERGENCY => 0,
-    ];
+    /** @var array<int, int> */
+    private $thresholdMap = [];
 
     /**
      * Buffer of all messages passed to the handler before the threshold was reached
@@ -61,12 +52,12 @@ class OverflowHandler extends AbstractHandler implements FormattableHandlerInter
 
     /**
      * @param HandlerInterface $handler
-     * @param int[]            $thresholdMap Dictionary of logger level => threshold
+     * @param array<int, int>  $thresholdMap Dictionary of log level value => threshold
      */
     public function __construct(
         HandlerInterface $handler,
         array $thresholdMap = [],
-        $level = Logger::DEBUG,
+        $level = Level::Debug,
         bool $bubble = true
     ) {
         $this->handler = $handler;
@@ -90,11 +81,11 @@ class OverflowHandler extends AbstractHandler implements FormattableHandlerInter
      */
     public function handle(LogRecord $record): bool
     {
-        if ($record->level < $this->level) {
+        if ($record->level->isLowerThan($this->level)) {
             return false;
         }
 
-        $level = $record->level;
+        $level = $record->level->value;
 
         if (!isset($this->thresholdMap[$level])) {
             $this->thresholdMap[$level] = 0;
diff --git a/src/Monolog/Handler/PHPConsoleHandler.php b/src/Monolog/Handler/PHPConsoleHandler.php
index d4aeb9e9..ff6c707f 100644
--- a/src/Monolog/Handler/PHPConsoleHandler.php
+++ b/src/Monolog/Handler/PHPConsoleHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\LineFormatter;
 use Monolog\Formatter\FormatterInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use PhpConsole\Connector;
 use PhpConsole\Handler as VendorPhpConsoleHandler;
@@ -73,7 +73,7 @@ class PHPConsoleHandler extends AbstractProcessingHandler
      * @param  Connector|null       $connector Instance of \PhpConsole\Connector class (optional)
      * @throws \RuntimeException
      */
-    public function __construct(array $options = [], ?Connector $connector = null, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(array $options = [], ?Connector $connector = null, $level = Level::Debug, bool $bubble = true)
     {
         if (!class_exists('PhpConsole\Connector')) {
             throw new \RuntimeException('PHP Console library not found. See https://github.com/barbushin/php-console#installation');
@@ -180,7 +180,7 @@ class PHPConsoleHandler extends AbstractProcessingHandler
      */
     protected function write(LogRecord $record): void
     {
-        if ($record->level < Logger::NOTICE) {
+        if ($record->level->isLowerThan(Level::Notice)) {
             $this->handleDebugRecord($record);
         } elseif (isset($record->context['exception']) && $record->context['exception'] instanceof \Throwable) {
             $this->handleExceptionRecord($record);
@@ -239,7 +239,7 @@ class PHPConsoleHandler extends AbstractProcessingHandler
             }
         }
 
-        return [$tags ?: strtolower($record->levelName), $filteredContext];
+        return [$tags ?: strtolower($record->levelName->value), $filteredContext];
     }
 
     /**
diff --git a/src/Monolog/Handler/ProcessHandler.php b/src/Monolog/Handler/ProcessHandler.php
index d2c3cea9..c43b8863 100644
--- a/src/Monolog/Handler/ProcessHandler.php
+++ b/src/Monolog/Handler/ProcessHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -64,7 +64,7 @@ class ProcessHandler extends AbstractProcessingHandler
      * @param  string|null               $cwd     "Current working directory" (CWD) for the process to be executed in.
      * @throws \InvalidArgumentException
      */
-    public function __construct(string $command, $level = Logger::DEBUG, bool $bubble = true, ?string $cwd = null)
+    public function __construct(string $command, $level = Level::Debug, bool $bubble = true, ?string $cwd = null)
     {
         if ($command === '') {
             throw new \InvalidArgumentException('The command argument must be a non-empty string.');
diff --git a/src/Monolog/Handler/PsrHandler.php b/src/Monolog/Handler/PsrHandler.php
index 50fee172..30369e27 100644
--- a/src/Monolog/Handler/PsrHandler.php
+++ b/src/Monolog/Handler/PsrHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Psr\Log\LoggerInterface;
 use Monolog\Formatter\FormatterInterface;
 use Monolog\LogRecord;
@@ -42,7 +42,7 @@ class PsrHandler extends AbstractHandler implements FormattableHandlerInterface
     /**
      * @param LoggerInterface $logger The underlying PSR-3 compliant logger to which messages will be proxied
      */
-    public function __construct(LoggerInterface $logger, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(LoggerInterface $logger, $level = Level::Debug, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
 
@@ -60,9 +60,9 @@ class PsrHandler extends AbstractHandler implements FormattableHandlerInterface
 
         if ($this->formatter) {
             $formatted = $this->formatter->format($record);
-            $this->logger->log(strtolower($record->levelName), (string) $formatted, $record->context);
+            $this->logger->log(strtolower($record->levelName->value), (string) $formatted, $record->context);
         } else {
-            $this->logger->log(strtolower($record->levelName), $record->message, $record->context);
+            $this->logger->log(strtolower($record->levelName->value), $record->message, $record->context);
         }
 
         return false === $this->bubble;
diff --git a/src/Monolog/Handler/PushoverHandler.php b/src/Monolog/Handler/PushoverHandler.php
index 57bdff8d..0e3db9dc 100644
--- a/src/Monolog/Handler/PushoverHandler.php
+++ b/src/Monolog/Handler/PushoverHandler.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Monolog\Utils;
 use Psr\Log\LogLevel;
@@ -21,9 +23,6 @@ use Monolog\LogRecord;
  *
  * @author Sebastian Göttschkes <sebastian.goettschkes@googlemail.com>
  * @see    https://www.pushover.net/api
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class PushoverHandler extends SocketHandler
 {
@@ -40,10 +39,8 @@ class PushoverHandler extends SocketHandler
     /** @var int */
     private $expire;
 
-    /** @var int */
-    private $highPriorityLevel;
-    /** @var int */
-    private $emergencyLevel;
+    private Level $highPriorityLevel;
+    private Level $emergencyLevel;
     /** @var bool */
     private $useFormattedMessage = false;
 
@@ -85,28 +82,30 @@ class PushoverHandler extends SocketHandler
      * @param string|null  $title             Title sent to the Pushover API
      * @param bool         $useSSL            Whether to connect via SSL. Required when pushing messages to users that are not
      *                                        the pushover.net app owner. OpenSSL is required for this option.
-     * @param string|int   $highPriorityLevel The minimum logging level at which this handler will start
-     *                                        sending "high priority" requests to the Pushover API
-     * @param string|int   $emergencyLevel    The minimum logging level at which this handler will start
-     *                                        sending "emergency" requests to the Pushover API
      * @param int          $retry             The retry parameter specifies how often (in seconds) the Pushover servers will
      *                                        send the same notification to the user.
      * @param int          $expire            The expire parameter specifies how many seconds your notification will continue
      *                                        to be retried for (every retry seconds).
      *
+     * @param int|string|Level|LevelName|LogLevel::* $highPriorityLevel The minimum logging level at which this handler will start
+     *                                                                  sending "high priority" requests to the Pushover API
+     * @param int|string|Level|LevelName|LogLevel::* $emergencyLevel    The minimum logging level at which this handler will start
+     *                                                                  sending "emergency" requests to the Pushover API
+     *
+     *
      * @phpstan-param string|array<int|string>    $users
-     * @phpstan-param Level|LevelName|LogLevel::* $highPriorityLevel
-     * @phpstan-param Level|LevelName|LogLevel::* $emergencyLevel
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $highPriorityLevel
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $emergencyLevel
      */
     public function __construct(
         string $token,
         $users,
         ?string $title = null,
-        $level = Logger::CRITICAL,
+        int|string|Level|LevelName $level = Level::Critical,
         bool $bubble = true,
         bool $useSSL = true,
-        $highPriorityLevel = Logger::CRITICAL,
-        $emergencyLevel = Logger::EMERGENCY,
+        int|string|Level|LevelName $highPriorityLevel = Level::Critical,
+        int|string|Level|LevelName $emergencyLevel = Level::Emergency,
         int $retry = 30,
         int $expire = 25200,
         bool $persistent = false,
@@ -161,11 +160,11 @@ class PushoverHandler extends SocketHandler
             'timestamp' => $timestamp,
         ];
 
-        if (isset($record->level) && $record->level >= $this->emergencyLevel) {
+        if ($record->level->value >= $this->emergencyLevel->value) {
             $dataArray['priority'] = 2;
             $dataArray['retry'] = $this->retry;
             $dataArray['expire'] = $this->expire;
-        } elseif (isset($record->level) && $record->level >= $this->highPriorityLevel) {
+        } elseif ($record->level->value >= $this->highPriorityLevel->value) {
             $dataArray['priority'] = 1;
         }
 
@@ -208,25 +207,25 @@ class PushoverHandler extends SocketHandler
     }
 
     /**
-     * @param int|string $value
+     * @param int|string|Level|LevelName|LogLevel::* $level
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $value
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function setHighPriorityLevel($value): self
+    public function setHighPriorityLevel(int|string|Level|LevelName $level): self
     {
-        $this->highPriorityLevel = Logger::toMonologLevel($value);
+        $this->highPriorityLevel = Logger::toMonologLevel($level);
 
         return $this;
     }
 
     /**
-     * @param int|string $value
+     * @param int|string|Level|LevelName|LogLevel::* $level
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $value
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function setEmergencyLevel($value): self
+    public function setEmergencyLevel(int|string|Level|LevelName $level): self
     {
-        $this->emergencyLevel = Logger::toMonologLevel($value);
+        $this->emergencyLevel = Logger::toMonologLevel($level);
 
         return $this;
     }
@@ -234,9 +233,9 @@ class PushoverHandler extends SocketHandler
     /**
      * Use the formatted message?
      */
-    public function useFormattedMessage(bool $value): self
+    public function useFormattedMessage(bool $useFormattedMessage): self
     {
-        $this->useFormattedMessage = $value;
+        $this->useFormattedMessage = $useFormattedMessage;
 
         return $this;
     }
diff --git a/src/Monolog/Handler/RedisHandler.php b/src/Monolog/Handler/RedisHandler.php
index 6b652ce5..eecbf837 100644
--- a/src/Monolog/Handler/RedisHandler.php
+++ b/src/Monolog/Handler/RedisHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\LineFormatter;
 use Monolog\Formatter\FormatterInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -41,7 +41,7 @@ class RedisHandler extends AbstractProcessingHandler
      * @param string                $key     The key name to push records to
      * @param int                   $capSize Number of entries to limit list size to, 0 = unlimited
      */
-    public function __construct($redis, string $key, $level = Logger::DEBUG, bool $bubble = true, int $capSize = 0)
+    public function __construct($redis, string $key, $level = Level::Debug, bool $bubble = true, int $capSize = 0)
     {
         if (!(($redis instanceof \Predis\Client) || ($redis instanceof \Redis))) {
             throw new \InvalidArgumentException('Predis\Client or Redis instance required');
diff --git a/src/Monolog/Handler/RedisPubSubHandler.php b/src/Monolog/Handler/RedisPubSubHandler.php
index 0d58ed28..01138cc7 100644
--- a/src/Monolog/Handler/RedisPubSubHandler.php
+++ b/src/Monolog/Handler/RedisPubSubHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\LineFormatter;
 use Monolog\Formatter\FormatterInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -22,7 +22,7 @@ use Monolog\LogRecord;
  * usage example:
  *
  *   $log = new Logger('application');
- *   $redis = new RedisPubSubHandler(new Predis\Client("tcp://localhost:6379"), "logs", Logger::WARNING);
+ *   $redis = new RedisPubSubHandler(new Predis\Client("tcp://localhost:6379"), "logs", Level::Warning);
  *   $log->pushHandler($redis);
  *
  * @author Gaëtan Faugère <gaetan@fauge.re>
@@ -38,7 +38,7 @@ class RedisPubSubHandler extends AbstractProcessingHandler
      * @param \Predis\Client<\Predis\Client>|\Redis $redis The redis instance
      * @param string                $key   The channel key to publish records to
      */
-    public function __construct($redis, string $key, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct($redis, string $key, $level = Level::Debug, bool $bubble = true)
     {
         if (!(($redis instanceof \Predis\Client) || ($redis instanceof \Redis))) {
             throw new \InvalidArgumentException('Predis\Client or Redis instance required');
diff --git a/src/Monolog/Handler/RollbarHandler.php b/src/Monolog/Handler/RollbarHandler.php
index 76b32054..1f082cd6 100644
--- a/src/Monolog/Handler/RollbarHandler.php
+++ b/src/Monolog/Handler/RollbarHandler.php
@@ -11,9 +11,10 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Rollbar\RollbarLogger;
 use Throwable;
-use Monolog\Logger;
 use Monolog\LogRecord;
 
 /**
@@ -39,18 +40,6 @@ class RollbarHandler extends AbstractProcessingHandler
      */
     protected $rollbarLogger;
 
-    /** @var string[] */
-    protected $levelMap = [
-        Logger::DEBUG     => 'debug',
-        Logger::INFO      => 'info',
-        Logger::NOTICE    => 'info',
-        Logger::WARNING   => 'warning',
-        Logger::ERROR     => 'error',
-        Logger::CRITICAL  => 'critical',
-        Logger::ALERT     => 'critical',
-        Logger::EMERGENCY => 'critical',
-    ];
-
     /**
      * Records whether any log records have been added since the last flush of the rollbar notifier
      *
@@ -64,13 +53,32 @@ class RollbarHandler extends AbstractProcessingHandler
     /**
      * @param RollbarLogger $rollbarLogger RollbarLogger object constructed with valid token
      */
-    public function __construct(RollbarLogger $rollbarLogger, $level = Logger::ERROR, bool $bubble = true)
+    public function __construct(RollbarLogger $rollbarLogger, int|string|Level|LevelName $level = Level::Error, bool $bubble = true)
     {
         $this->rollbarLogger = $rollbarLogger;
 
         parent::__construct($level, $bubble);
     }
 
+    /**
+     * Translates Monolog log levels to Rollbar levels.
+     *
+     * @return 'debug'|'info'|'warning'|'error'|'critical'
+     */
+    protected function toRollbarLevel(Level $level): string
+    {
+        return match ($level) {
+            Level::Debug     => 'debug',
+            Level::Info      => 'info',
+            Level::Notice    => 'info',
+            Level::Warning   => 'warning',
+            Level::Error     => 'error',
+            Level::Critical  => 'critical',
+            Level::Alert     => 'critical',
+            Level::Emergency => 'critical',
+        };
+    }
+
     /**
      * {@inheritDoc}
      */
@@ -84,7 +92,7 @@ class RollbarHandler extends AbstractProcessingHandler
 
         $context = $record->context;
         $context = array_merge($context, $record->extra, [
-            'level' => $this->levelMap[$record->level],
+            'level' => $this->toRollbarLevel($record->level),
             'monolog_level' => $record->levelName,
             'channel' => $record->channel,
             'datetime' => $record->datetime->format('U'),
diff --git a/src/Monolog/Handler/RotatingFileHandler.php b/src/Monolog/Handler/RotatingFileHandler.php
index 39abfc95..e7d27aac 100644
--- a/src/Monolog/Handler/RotatingFileHandler.php
+++ b/src/Monolog/Handler/RotatingFileHandler.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use InvalidArgumentException;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -50,7 +50,7 @@ class RotatingFileHandler extends StreamHandler
      * @param int|null   $filePermission Optional file permissions (default (0644) are only for owner read/write)
      * @param bool       $useLocking     Try to lock log file before doing any writes
      */
-    public function __construct(string $filename, int $maxFiles = 0, $level = Logger::DEBUG, bool $bubble = true, ?int $filePermission = null, bool $useLocking = false)
+    public function __construct(string $filename, int $maxFiles = 0, $level = Level::Debug, bool $bubble = true, ?int $filePermission = null, bool $useLocking = false)
     {
         $this->filename = Utils::canonicalizePath($filename);
         $this->maxFiles = $maxFiles;
diff --git a/src/Monolog/Handler/SamplingHandler.php b/src/Monolog/Handler/SamplingHandler.php
index 39f1e0d7..8238de84 100644
--- a/src/Monolog/Handler/SamplingHandler.php
+++ b/src/Monolog/Handler/SamplingHandler.php
@@ -27,7 +27,6 @@ use Monolog\LogRecord;
  *
  * @author Bryan Davis <bd808@wikimedia.org>
  * @author Kunal Mehta <legoktm@gmail.com>
- * @phpstan-import-type Level from \Monolog\Logger
  */
 class SamplingHandler extends AbstractHandler implements ProcessableHandlerInterface, FormattableHandlerInterface
 {
diff --git a/src/Monolog/Handler/SendGridHandler.php b/src/Monolog/Handler/SendGridHandler.php
index 1280ee70..50b23e2c 100644
--- a/src/Monolog/Handler/SendGridHandler.php
+++ b/src/Monolog/Handler/SendGridHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * SendGridrHandler uses the SendGrid API v2 function to send Log emails, more information in https://sendgrid.com/docs/API_Reference/Web_API/mail.html
@@ -57,7 +57,7 @@ class SendGridHandler extends MailHandler
      * @param string|string[] $to      The recipients of the email
      * @param string          $subject The subject of the mail
      */
-    public function __construct(string $apiUser, string $apiKey, string $from, $to, string $subject, $level = Logger::ERROR, bool $bubble = true)
+    public function __construct(string $apiUser, string $apiKey, string $from, $to, string $subject, $level = Level::Error, bool $bubble = true)
     {
         if (!extension_loaded('curl')) {
             throw new MissingExtensionException('The curl extension is needed to use the SendGridHandler');
diff --git a/src/Monolog/Handler/Slack/SlackRecord.php b/src/Monolog/Handler/Slack/SlackRecord.php
index 7e9e3233..0a87babf 100644
--- a/src/Monolog/Handler/Slack/SlackRecord.php
+++ b/src/Monolog/Handler/Slack/SlackRecord.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler\Slack;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\Formatter\NormalizerFormatter;
 use Monolog\Formatter\FormatterInterface;
@@ -145,7 +145,7 @@ class SlackRecord
             $attachment = array(
                 'fallback'  => $message,
                 'text'      => $message,
-                'color'     => $this->getAttachmentColor($recordData['level']),
+                'color'     => $this->getAttachmentColor($record->level),
                 'fields'    => array(),
                 'mrkdwn_in' => array('fields'),
                 'ts'        => $recordData['datetime']->getTimestamp(),
@@ -201,18 +201,14 @@ class SlackRecord
      * Returns a Slack message attachment color associated with
      * provided level.
      */
-    public function getAttachmentColor(int $level): string
+    public function getAttachmentColor(Level $level): string
     {
-        switch (true) {
-            case $level >= Logger::ERROR:
-                return static::COLOR_DANGER;
-            case $level >= Logger::WARNING:
-                return static::COLOR_WARNING;
-            case $level >= Logger::INFO:
-                return static::COLOR_GOOD;
-            default:
-                return static::COLOR_DEFAULT;
-        }
+        return match ($level) {
+            Level::Error, Level::Critical, Level::Alert, Level::Emergency => static::COLOR_DANGER,
+            Level::Warning => static::COLOR_WARNING,
+            Level::Info, Level::Notice => static::COLOR_GOOD,
+            Level::Debug => static::COLOR_DEFAULT
+        };
     }
 
     /**
diff --git a/src/Monolog/Handler/SlackHandler.php b/src/Monolog/Handler/SlackHandler.php
index 4f57daee..fb85cd01 100644
--- a/src/Monolog/Handler/SlackHandler.php
+++ b/src/Monolog/Handler/SlackHandler.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Formatter\FormatterInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\Handler\Slack\SlackRecord;
 use Monolog\LogRecord;
@@ -54,7 +54,7 @@ class SlackHandler extends SocketHandler
         ?string $username = null,
         bool $useAttachment = true,
         ?string $iconEmoji = null,
-        $level = Logger::CRITICAL,
+        $level = Level::Critical,
         bool $bubble = true,
         bool $useShortAttachment = false,
         bool $includeContextAndExtra = false,
diff --git a/src/Monolog/Handler/SlackWebhookHandler.php b/src/Monolog/Handler/SlackWebhookHandler.php
index 269b6995..c98c1c3d 100644
--- a/src/Monolog/Handler/SlackWebhookHandler.php
+++ b/src/Monolog/Handler/SlackWebhookHandler.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Formatter\FormatterInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\Handler\Slack\SlackRecord;
 use Monolog\LogRecord;
@@ -55,7 +55,7 @@ class SlackWebhookHandler extends AbstractProcessingHandler
         ?string $iconEmoji = null,
         bool $useShortAttachment = false,
         bool $includeContextAndExtra = false,
-        $level = Logger::CRITICAL,
+        $level = Level::Critical,
         bool $bubble = true,
         array $excludeFields = array()
     ) {
diff --git a/src/Monolog/Handler/SocketHandler.php b/src/Monolog/Handler/SocketHandler.php
index 1d8a68f2..727666c4 100644
--- a/src/Monolog/Handler/SocketHandler.php
+++ b/src/Monolog/Handler/SocketHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -58,7 +58,7 @@ class SocketHandler extends AbstractProcessingHandler
      */
     public function __construct(
         string $connectionString,
-        $level = Logger::DEBUG,
+        $level = Level::Debug,
         bool $bubble = true,
         bool $persistent = false,
         float $timeout = 0.0,
diff --git a/src/Monolog/Handler/SqsHandler.php b/src/Monolog/Handler/SqsHandler.php
index 727c20a8..fe9e1ecd 100644
--- a/src/Monolog/Handler/SqsHandler.php
+++ b/src/Monolog/Handler/SqsHandler.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Aws\Sqs\SqsClient;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -33,7 +33,7 @@ class SqsHandler extends AbstractProcessingHandler
     /** @var string */
     private $queueUrl;
 
-    public function __construct(SqsClient $sqsClient, string $queueUrl, $level = Logger::DEBUG, bool $bubble = true)
+    public function __construct(SqsClient $sqsClient, string $queueUrl, $level = Level::Debug, bool $bubble = true)
     {
         parent::__construct($level, $bubble);
 
diff --git a/src/Monolog/Handler/StreamHandler.php b/src/Monolog/Handler/StreamHandler.php
index 0053db15..328c4ea6 100644
--- a/src/Monolog/Handler/StreamHandler.php
+++ b/src/Monolog/Handler/StreamHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -50,7 +50,7 @@ class StreamHandler extends AbstractProcessingHandler
      *
      * @throws \InvalidArgumentException If stream is not a resource or string
      */
-    public function __construct($stream, $level = Logger::DEBUG, bool $bubble = true, ?int $filePermission = null, bool $useLocking = false)
+    public function __construct($stream, $level = Level::Debug, bool $bubble = true, ?int $filePermission = null, bool $useLocking = false)
     {
         parent::__construct($level, $bubble);
 
diff --git a/src/Monolog/Handler/SyslogHandler.php b/src/Monolog/Handler/SyslogHandler.php
index 77ceaa1d..73d28681 100644
--- a/src/Monolog/Handler/SyslogHandler.php
+++ b/src/Monolog/Handler/SyslogHandler.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -40,7 +40,7 @@ class SyslogHandler extends AbstractSyslogHandler
      * @param string|int $facility Either one of the names of the keys in $this->facilities, or a LOG_* facility constant
      * @param int        $logopts  Option flags for the openlog() call, defaults to LOG_PID
      */
-    public function __construct(string $ident, $facility = LOG_USER, $level = Logger::DEBUG, bool $bubble = true, int $logopts = LOG_PID)
+    public function __construct(string $ident, $facility = LOG_USER, $level = Level::Debug, bool $bubble = true, int $logopts = LOG_PID)
     {
         parent::__construct($facility, $level, $bubble);
 
@@ -64,6 +64,6 @@ class SyslogHandler extends AbstractSyslogHandler
         if (!openlog($this->ident, $this->logopts, $this->facility)) {
             throw new \LogicException('Can\'t open syslog for ident "'.$this->ident.'" and facility "'.$this->facility.'"' . Utils::getRecordMessageForException($record));
         }
-        syslog($this->logLevels[$record->level], (string) $record->formatted);
+        syslog($this->toSyslogPriority($record->level), (string) $record->formatted);
     }
 }
diff --git a/src/Monolog/Handler/SyslogUdpHandler.php b/src/Monolog/Handler/SyslogUdpHandler.php
index 07feaa56..7fe92b14 100644
--- a/src/Monolog/Handler/SyslogUdpHandler.php
+++ b/src/Monolog/Handler/SyslogUdpHandler.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use DateTimeInterface;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Handler\SyslogUdp\UdpSocket;
 use Monolog\Utils;
 use Monolog\LogRecord;
@@ -54,7 +54,7 @@ class SyslogUdpHandler extends AbstractSyslogHandler
      *
      * @phpstan-param self::RFC* $rfc
      */
-    public function __construct(string $host, int $port = 514, $facility = LOG_USER, $level = Logger::DEBUG, bool $bubble = true, string $ident = 'php', int $rfc = self::RFC5424)
+    public function __construct(string $host, int $port = 514, $facility = LOG_USER, $level = Level::Debug, bool $bubble = true, string $ident = 'php', int $rfc = self::RFC5424)
     {
         if (!extension_loaded('sockets')) {
             throw new MissingExtensionException('The sockets extension is required to use the SyslogUdpHandler');
@@ -72,7 +72,7 @@ class SyslogUdpHandler extends AbstractSyslogHandler
     {
         $lines = $this->splitMessageIntoLines($record->formatted);
 
-        $header = $this->makeCommonSyslogHeader($this->logLevels[$record->level], $record->datetime);
+        $header = $this->makeCommonSyslogHeader($this->toSyslogPriority($record->level), $record->datetime);
 
         foreach ($lines as $line) {
             $this->socket->write($line, $header);
diff --git a/src/Monolog/Handler/TelegramBotHandler.php b/src/Monolog/Handler/TelegramBotHandler.php
index e2812c99..0d22455c 100644
--- a/src/Monolog/Handler/TelegramBotHandler.php
+++ b/src/Monolog/Handler/TelegramBotHandler.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use RuntimeException;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Utils;
 use Monolog\LogRecord;
 
@@ -105,7 +105,7 @@ class TelegramBotHandler extends AbstractProcessingHandler
     public function __construct(
         string $apiKey,
         string $channel,
-               $level = Logger::DEBUG,
+               $level = Level::Debug,
         bool   $bubble = true,
         string $parseMode = null,
         bool   $disableWebPagePreview = null,
diff --git a/src/Monolog/Handler/TestHandler.php b/src/Monolog/Handler/TestHandler.php
index 2395889e..53143598 100644
--- a/src/Monolog/Handler/TestHandler.php
+++ b/src/Monolog/Handler/TestHandler.php
@@ -11,10 +11,11 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Psr\Log\LogLevel;
 use Monolog\LogRecord;
-use Monolog\DateTimeImmutable;
 
 /**
  * Used for testing purposes.
@@ -67,16 +68,13 @@ use Monolog\DateTimeImmutable;
  * @method bool hasNoticeThatPasses($message)
  * @method bool hasInfoThatPasses($message)
  * @method bool hasDebugThatPasses($message)
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class TestHandler extends AbstractProcessingHandler
 {
     /** @var LogRecord[] */
     protected $records = [];
-    /** @var array<Level, LogRecord[]> */
-    protected $recordsByLevel = [];
+    /** @phpstan-var array<value-of<Level::VALUES>, LogRecord[]> */
+    protected array $recordsByLevel = [];
     /** @var bool */
     private $skipReset = false;
 
@@ -116,23 +114,21 @@ class TestHandler extends AbstractProcessingHandler
     }
 
     /**
-     * @param string|int $level Logging level value or name
+     * @param int|string|Level|LevelName|LogLevel::* $level Logging level value or name
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function hasRecords($level): bool
+    public function hasRecords(int|string|Level|LevelName $level): bool
     {
-        return isset($this->recordsByLevel[Logger::toMonologLevel($level)]);
+        return isset($this->recordsByLevel[Logger::toMonologLevel($level)->value]);
     }
 
     /**
      * @param string|array $recordAssertions Either a message string or an array containing message and optionally context keys that will be checked against all records
-     * @param string|int   $level  Logging level value or name
      *
      * @phpstan-param array{message: string, context?: mixed[]}|string $recordAssertions
-     * @phpstan-param Level|LevelName|LogLevel::*                      $level
      */
-    public function hasRecord(string|array $recordAssertions, $level): bool
+    public function hasRecord(string|array $recordAssertions, Level $level): bool
     {
         if (is_string($recordAssertions)) {
             $recordAssertions = ['message' => $recordAssertions];
@@ -150,42 +146,28 @@ class TestHandler extends AbstractProcessingHandler
         }, $level);
     }
 
-    /**
-     * @param string|int $level Logging level value or name
-     *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
-     */
-    public function hasRecordThatContains(string $message, $level): bool
+    public function hasRecordThatContains(string $message, Level $level): bool
     {
         return $this->hasRecordThatPasses(fn (LogRecord $rec) => str_contains($rec->message, $message), $level);
     }
 
-    /**
-     * @param string|int $level Logging level value or name
-     *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
-     */
-    public function hasRecordThatMatches(string $regex, $level): bool
+    public function hasRecordThatMatches(string $regex, Level $level): bool
     {
         return $this->hasRecordThatPasses(fn (LogRecord $rec) => preg_match($regex, $rec->message) > 0, $level);
     }
 
     /**
-     * @param  string|int $level Logging level value or name
-     * @return bool
-     *
      * @phpstan-param callable(LogRecord, int): mixed $predicate
-     * @phpstan-param Level|LevelName|LogLevel::* $level
      */
-    public function hasRecordThatPasses(callable $predicate, $level)
+    public function hasRecordThatPasses(callable $predicate, Level $level): bool
     {
         $level = Logger::toMonologLevel($level);
 
-        if (!isset($this->recordsByLevel[$level])) {
+        if (!isset($this->recordsByLevel[$level->value])) {
             return false;
         }
 
-        foreach ($this->recordsByLevel[$level] as $i => $rec) {
+        foreach ($this->recordsByLevel[$level->value] as $i => $rec) {
             if ($predicate($rec, $i)) {
                 return true;
             }
@@ -199,7 +181,7 @@ class TestHandler extends AbstractProcessingHandler
      */
     protected function write(LogRecord $record): void
     {
-        $this->recordsByLevel[$record->level][] = $record;
+        $this->recordsByLevel[$record->level->value][] = $record;
         $this->records[] = $record;
     }
 
@@ -212,11 +194,10 @@ class TestHandler extends AbstractProcessingHandler
     {
         if (preg_match('/(.*)(Debug|Info|Notice|Warning|Error|Critical|Alert|Emergency)(.*)/', $method, $matches) > 0) {
             $genericMethod = $matches[1] . ('Records' !== $matches[3] ? 'Record' : '') . $matches[3];
-            $level = constant('Monolog\Logger::' . strtoupper($matches[2]));
+            $level = constant(Level::class.'::' . $matches[2]);
             $callback = [$this, $genericMethod];
             if (is_callable($callback)) {
                 $args[] = $level;
-
                 return call_user_func_array($callback, $args);
             }
         }
diff --git a/src/Monolog/Handler/ZendMonitorHandler.php b/src/Monolog/Handler/ZendMonitorHandler.php
index b881f492..32f9c611 100644
--- a/src/Monolog/Handler/ZendMonitorHandler.php
+++ b/src/Monolog/Handler/ZendMonitorHandler.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\FormatterInterface;
 use Monolog\Formatter\NormalizerFormatter;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 
 /**
@@ -24,47 +24,48 @@ use Monolog\LogRecord;
  */
 class ZendMonitorHandler extends AbstractProcessingHandler
 {
-    /**
-     * Monolog level / ZendMonitor Custom Event priority map
-     *
-     * @var array<int, int>
-     */
-    protected $levelMap = [];
-
     /**
      * @throws MissingExtensionException
      */
-    public function __construct($level = Logger::DEBUG, bool $bubble = true)
+    public function __construct($level = Level::Debug, bool $bubble = true)
     {
         if (!function_exists('zend_monitor_custom_event')) {
             throw new MissingExtensionException(
                 'You must have Zend Server installed with Zend Monitor enabled in order to use this handler'
             );
         }
-        //zend monitor constants are not defined if zend monitor is not enabled.
-        $this->levelMap = [
-            Logger::DEBUG     => \ZEND_MONITOR_EVENT_SEVERITY_INFO,
-            Logger::INFO      => \ZEND_MONITOR_EVENT_SEVERITY_INFO,
-            Logger::NOTICE    => \ZEND_MONITOR_EVENT_SEVERITY_INFO,
-            Logger::WARNING   => \ZEND_MONITOR_EVENT_SEVERITY_WARNING,
-            Logger::ERROR     => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
-            Logger::CRITICAL  => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
-            Logger::ALERT     => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
-            Logger::EMERGENCY => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
-        ];
+
         parent::__construct($level, $bubble);
     }
 
+    /**
+     * Translates Monolog log levels to ZendMonitor levels.
+     */
+    protected function toZendMonitorLevel(Level $level): int
+    {
+        return match ($level) {
+            Level::Debug     => \ZEND_MONITOR_EVENT_SEVERITY_INFO,
+            Level::Info      => \ZEND_MONITOR_EVENT_SEVERITY_INFO,
+            Level::Notice    => \ZEND_MONITOR_EVENT_SEVERITY_INFO,
+            Level::Warning   => \ZEND_MONITOR_EVENT_SEVERITY_WARNING,
+            Level::Error     => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
+            Level::Critical  => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
+            Level::Alert     => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
+            Level::Emergency => \ZEND_MONITOR_EVENT_SEVERITY_ERROR,
+        };
+    }
+
+
     /**
      * {@inheritDoc}
      */
     protected function write(LogRecord $record): void
     {
         $this->writeZendMonitorCustomEvent(
-            Logger::getLevelName($record->level),
+            $record->level->toLevelName()->value,
             $record->message,
             $record->formatted,
-            $this->levelMap[$record->level]
+            $this->toZendMonitorLevel($record->level)
         );
     }
 
@@ -87,12 +88,4 @@ class ZendMonitorHandler extends AbstractProcessingHandler
     {
         return new NormalizerFormatter();
     }
-
-    /**
-     * @return array<int, int>
-     */
-    public function getLevelMap(): array
-    {
-        return $this->levelMap;
-    }
 }
diff --git a/src/Monolog/Level.php b/src/Monolog/Level.php
new file mode 100644
index 00000000..70c39486
--- /dev/null
+++ b/src/Monolog/Level.php
@@ -0,0 +1,127 @@
+<?php
+
+namespace Monolog;
+
+use Psr\Log\LogLevel;
+
+/**
+ * @see LevelName
+ */
+enum Level: int
+{
+    /**
+     * Detailed debug information
+     */
+    case Debug = 100;
+
+    /**
+     * Interesting events
+     *
+     * Examples: User logs in, SQL logs.
+     */
+    case Info = 200;
+
+    /**
+     * Uncommon events
+     */
+    case Notice = 250;
+
+    /**
+     * Exceptional occurrences that are not errors
+     *
+     * Examples: Use of deprecated APIs, poor use of an API,
+     * undesirable things that are not necessarily wrong.
+     */
+    case Warning = 300;
+
+    /**
+     * Runtime errors
+     */
+    case Error = 400;
+
+    /**
+     * Critical conditions
+     *
+     * Example: Application component unavailable, unexpected exception.
+     */
+    case Critical = 500;
+
+    /**
+     * Action must be taken immediately
+     *
+     * Example: Entire website down, database unavailable, etc.
+     * This should trigger the SMS alerts and wake you up.
+     */
+    case Alert = 550;
+
+    /**
+     * Urgent alert.
+     */
+    case Emergency = 600;
+
+    public static function fromLevelName(LevelName $name): self
+    {
+        return match ($name) {
+            LevelName::Debug => self::Debug,
+            LevelName::Info => self::Info,
+            LevelName::Notice => self::Notice,
+            LevelName::Warning => self::Warning,
+            LevelName::Error => self::Error,
+            LevelName::Critical => self::Critical,
+            LevelName::Alert => self::Alert,
+            LevelName::Emergency => self::Emergency,
+        };
+    }
+
+    /**
+     * Returns true if the passed $level is higher or equal to $this
+     */
+    public function includes(Level $level): bool
+    {
+        return $this->value <= $level->value;
+    }
+
+    public function isHigherThan(Level $level): bool
+    {
+        return $this->value > $level->value;
+    }
+
+    public function isLowerThan(Level $level): bool
+    {
+        return $this->value < $level->value;
+    }
+
+    public function toLevelName(): LevelName
+    {
+        return LevelName::fromLevel($this);
+    }
+
+    /**
+     * @return string
+     * @phpstan-return \Psr\Log\LogLevel::*
+     */
+    public function toPsrLogLevel(): string
+    {
+        return match ($this) {
+            self::Debug => LogLevel::DEBUG,
+            self::Info => LogLevel::INFO,
+            self::Notice => LogLevel::NOTICE,
+            self::Warning => LogLevel::WARNING,
+            self::Error => LogLevel::ERROR,
+            self::Critical => LogLevel::CRITICAL,
+            self::Alert => LogLevel::ALERT,
+            self::Emergency => LogLevel::EMERGENCY,
+        };
+    }
+
+    public const VALUES = [
+        100,
+        200,
+        250,
+        300,
+        400,
+        500,
+        550,
+        600,
+    ];
+}
diff --git a/src/Monolog/LevelName.php b/src/Monolog/LevelName.php
new file mode 100644
index 00000000..7d26d9f1
--- /dev/null
+++ b/src/Monolog/LevelName.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Monolog;
+
+/**
+ * @see Level
+ */
+enum LevelName: string
+{
+    case Debug = 'DEBUG';
+    case Info = 'INFO';
+    case Notice = 'NOTICE';
+    case Warning = 'WARNING';
+    case Error = 'ERROR';
+    case Critical = 'CRITICAL';
+    case Alert = 'ALERT';
+    case Emergency = 'EMERGENCY';
+
+    public static function fromLevel(Level $level): self
+    {
+        return match ($level) {
+            Level::Debug => self::Debug,
+            Level::Info => self::Info,
+            Level::Notice => self::Notice,
+            Level::Warning => self::Warning,
+            Level::Error => self::Error,
+            Level::Critical => self::Critical,
+            Level::Alert => self::Alert,
+            Level::Emergency => self::Emergency,
+        };
+    }
+
+    public function toLevel(): Level
+    {
+        return Level::fromLevelName($this);
+    }
+
+    public const VALUES = [
+        'DEBUG',
+        'INFO',
+        'NOTICE',
+        'WARNING',
+        'ERROR',
+        'CRITICAL',
+        'ALERT',
+        'EMERGENCY',
+    ];
+
+    public function jsonSerialize(): mixed
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Monolog/LogRecord.php b/src/Monolog/LogRecord.php
index 1e6aa07a..47fc66c7 100644
--- a/src/Monolog/LogRecord.php
+++ b/src/Monolog/LogRecord.php
@@ -17,25 +17,21 @@ use ArrayAccess;
  * Monolog log record
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- * @template-implements \ArrayAccess<'message'|'level'|'context'|'level_name'|'channel'|'datetime'|'extra', int|string|\DateTimeImmutable|array<mixed>>
- * @phpstan-import-type Level from Logger
- * @phpstan-import-type LevelName from Logger
+ * @template-implements ArrayAccess<'message'|'level'|'context'|'level_name'|'channel'|'datetime'|'extra', int|string|\DateTimeImmutable|array<mixed>>
  */
-class LogRecord implements \ArrayAccess
+class LogRecord implements ArrayAccess
 {
     private const MODIFIABLE_FIELDS = [
         'extra' => true,
         'formatted' => true,
     ];
 
-    /** @var 'DEBUG'|'INFO'|'NOTICE'|'WARNING'|'ERROR'|'CRITICAL'|'ALERT'|'EMERGENCY' */
-    public readonly string $levelName; // TODO enum?
+    public readonly LevelName $levelName;
 
     public function __construct(
         public readonly \DateTimeImmutable $datetime,
         public readonly string $channel,
-        /** @var Logger::DEBUG|Logger::INFO|Logger::NOTICE|Logger::WARNING|Logger::ERROR|Logger::CRITICAL|Logger::ALERT|Logger::EMERGENCY */
-        public readonly int $level, // TODO enum?
+        public readonly Level $level,
         public readonly string $message,
         /** @var array<mixed> */
         public readonly array $context = [],
@@ -43,7 +39,7 @@ class LogRecord implements \ArrayAccess
         public array $extra = [],
         public mixed $formatted = null,
     ) {
-        $this->levelName = Logger::getLevelName($level);
+        $this->levelName = LevelName::fromLevel($level);
     }
 
     public function offsetSet(mixed $offset, mixed $value): void
@@ -81,8 +77,15 @@ class LogRecord implements \ArrayAccess
 
     public function &offsetGet(mixed $offset): mixed
     {
-        if ($offset === 'level_name') {
-            $offset = 'levelName';
+        if ($offset === 'level_name' || $offset === 'level') {
+            if ($offset === 'level_name') {
+                $offset = 'levelName';
+            }
+
+            // avoid returning readonly props by ref as this is illegal
+            $copy = $this->{$offset}->value;
+
+            return $copy;
         }
 
         if (isset(self::MODIFIABLE_FIELDS[$offset])) {
@@ -96,15 +99,15 @@ class LogRecord implements \ArrayAccess
     }
 
     /**
-     * @phpstan-return array{message: string, context: mixed[], level: Level, level_name: LevelName, channel: string, datetime: \DateTimeImmutable, extra: mixed[]}
+     * @phpstan-return array{message: string, context: mixed[], level: value-of<Level::VALUES>, level_name: value-of<LevelName::VALUES>, channel: string, datetime: \DateTimeImmutable, extra: mixed[]}
      */
     public function toArray(): array
     {
         return [
             'message' => $this->message,
             'context' => $this->context,
-            'level' => $this->level,
-            'level_name' => $this->levelName,
+            'level' => $this->level->value,
+            'level_name' => $this->levelName->value,
             'channel' => $this->channel,
             'datetime' => $this->datetime,
             'extra' => $this->extra,
diff --git a/src/Monolog/Logger.php b/src/Monolog/Logger.php
index 88243844..bf985d2c 100644
--- a/src/Monolog/Logger.php
+++ b/src/Monolog/Logger.php
@@ -27,14 +27,13 @@ use Stringable;
  * and uses them to store records that are added to it.
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- *
- * @phpstan-type Level Logger::DEBUG|Logger::INFO|Logger::NOTICE|Logger::WARNING|Logger::ERROR|Logger::CRITICAL|Logger::ALERT|Logger::EMERGENCY
- * @phpstan-type LevelName 'DEBUG'|'INFO'|'NOTICE'|'WARNING'|'ERROR'|'CRITICAL'|'ALERT'|'EMERGENCY'
  */
 class Logger implements LoggerInterface, ResettableInterface
 {
     /**
      * Detailed debug information
+     *
+     * @deprecated Use \Monolog\Level::Debug
      */
     public const DEBUG = 100;
 
@@ -42,11 +41,15 @@ class Logger implements LoggerInterface, ResettableInterface
      * Interesting events
      *
      * Examples: User logs in, SQL logs.
+     *
+     * @deprecated Use \Monolog\Level::Info
      */
     public const INFO = 200;
 
     /**
      * Uncommon events
+     *
+     * @deprecated Use \Monolog\Level::Notice
      */
     public const NOTICE = 250;
 
@@ -55,11 +58,15 @@ class Logger implements LoggerInterface, ResettableInterface
      *
      * Examples: Use of deprecated APIs, poor use of an API,
      * undesirable things that are not necessarily wrong.
+     *
+     * @deprecated Use \Monolog\Level::Warning
      */
     public const WARNING = 300;
 
     /**
      * Runtime errors
+     *
+     * @deprecated Use \Monolog\Level::Error
      */
     public const ERROR = 400;
 
@@ -67,6 +74,8 @@ class Logger implements LoggerInterface, ResettableInterface
      * Critical conditions
      *
      * Example: Application component unavailable, unexpected exception.
+     *
+     * @deprecated Use \Monolog\Level::Critical
      */
     public const CRITICAL = 500;
 
@@ -75,11 +84,15 @@ class Logger implements LoggerInterface, ResettableInterface
      *
      * Example: Entire website down, database unavailable, etc.
      * This should trigger the SMS alerts and wake you up.
+     *
+     * @deprecated Use \Monolog\Level::Alert
      */
     public const ALERT = 550;
 
     /**
      * Urgent alert.
+     *
+     * @deprecated Use \Monolog\Level::Emergency
      */
     public const EMERGENCY = 600;
 
@@ -91,25 +104,7 @@ class Logger implements LoggerInterface, ResettableInterface
      *
      * @var int
      */
-    public const API = 2;
-
-    /**
-     * This is a static variable and not a constant to serve as an extension point for custom levels
-     *
-     * @var array<int, string> $levels Logging levels with the levels as key
-     *
-     * @phpstan-var array<Level, LevelName> $levels Logging levels with the levels as key
-     */
-    protected static $levels = [
-        self::DEBUG     => 'DEBUG',
-        self::INFO      => 'INFO',
-        self::NOTICE    => 'NOTICE',
-        self::WARNING   => 'WARNING',
-        self::ERROR     => 'ERROR',
-        self::CRITICAL  => 'CRITICAL',
-        self::ALERT     => 'ALERT',
-        self::EMERGENCY => 'EMERGENCY',
-    ];
+    public const API = 3;
 
     /**
      * @var string
@@ -287,16 +282,16 @@ class Logger implements LoggerInterface, ResettableInterface
      * @param  mixed[] $context The log context
      * @return bool    Whether the record has been processed
      *
-     * @phpstan-param Level $level
+     * @phpstan-param value-of<Level::VALUES>|Level $level
      */
-    public function addRecord(int $level, string $message, array $context = []): bool
+    public function addRecord(int|Level $level, string $message, array $context = []): bool
     {
         $recordInitialized = count($this->processors) === 0;
 
         $record = new LogRecord(
             message: $message,
             context: $context,
-            level: $level,
+            level: self::toMonologLevel($level),
             channel: $this->name,
             datetime: new DateTimeImmutable($this->microsecondTimestamps, $this->timezone),
             extra: [],
@@ -380,79 +375,64 @@ class Logger implements LoggerInterface, ResettableInterface
         }
     }
 
-    /**
-     * Gets all supported logging levels.
-     *
-     * @return array<string, int> Assoc array with human-readable level names => level codes.
-     * @phpstan-return array<LevelName, Level>
-     */
-    public static function getLevels(): array
-    {
-        return array_flip(static::$levels);
-    }
-
-    /**
-     * Gets the name of the logging level.
-     *
-     * @throws \Psr\Log\InvalidArgumentException If level is not defined
-     *
-     * @phpstan-param  Level     $level
-     * @phpstan-return LevelName
-     */
-    public static function getLevelName(int $level): string
-    {
-        if (!isset(static::$levels[$level])) {
-            throw new InvalidArgumentException('Level "'.$level.'" is not defined, use one of: '.implode(', ', array_keys(static::$levels)));
-        }
-
-        return static::$levels[$level];
-    }
-
     /**
      * Converts PSR-3 levels to Monolog ones if necessary
      *
-     * @param  string|int                        $level Level number (monolog) or name (PSR-3)
+     * @param  int|string|Level|LevelName|LogLevel::* $level Level number (monolog) or name (PSR-3)
      * @throws \Psr\Log\InvalidArgumentException If level is not defined
      *
-     * @phpstan-param  Level|LevelName|LogLevel::* $level
-     * @phpstan-return Level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public static function toMonologLevel($level): int
+    public static function toMonologLevel(string|int|Level|LevelName $level): Level
     {
-        if (is_string($level)) {
-            if (is_numeric($level)) {
-                return intval($level);
+        if ($level instanceof Level) {
+            return $level;
+        }
+
+        if ($level instanceof LevelName) {
+            return $level->toLevel();
+        }
+
+        if (\is_string($level)) {
+            if (\is_numeric($level)) {
+                $levelEnum = Level::tryFrom((int) $level);
+                if ($levelEnum === null) {
+                    throw new InvalidArgumentException('Level "'.$level.'" is not defined, use one of: '.implode(', ', LevelName::VALUES + Level::VALUES));
+                }
+
+                return $levelEnum;
             }
 
-            // Contains chars of all log levels and avoids using strtoupper() which may have
+            // Contains first char of all log levels and avoids using strtoupper() which may have
             // strange results depending on locale (for example, "i" will become "İ" in Turkish locale)
-            $upper = strtr($level, 'abcdefgilmnortuwy', 'ABCDEFGILMNORTUWY');
-            if (defined(__CLASS__.'::'.$upper)) {
-                return constant(__CLASS__ . '::' . $upper);
+            $upper = strtr(substr($level, 0, 1), 'dinweca', 'DINWECA') . strtolower(substr($level, 1));
+            if (defined(Level::class.'::'.$upper)) {
+                return constant(Level::class . '::' . $upper);
             }
 
-            throw new InvalidArgumentException('Level "'.$level.'" is not defined, use one of: '.implode(', ', array_keys(static::$levels) + static::$levels));
+            throw new InvalidArgumentException('Level "'.$level.'" is not defined, use one of: '.implode(', ', LevelName::VALUES + Level::VALUES));
         }
 
-        if (!is_int($level)) {
-            throw new InvalidArgumentException('Level "'.var_export($level, true).'" is not defined, use one of: '.implode(', ', array_keys(static::$levels) + static::$levels));
+        $levelEnum = Level::tryFrom($level);
+        if ($levelEnum === null) {
+            throw new InvalidArgumentException('Level "'.var_export($level, true).'" is not defined, use one of: '.implode(', ', LevelName::VALUES + Level::VALUES));
         }
 
-        return $level;
+        return $levelEnum;
     }
 
     /**
      * Checks whether the Logger has a handler that listens on the given level
      *
-     * @phpstan-param Level $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function isHandling(int $level): bool
+    public function isHandling(int|string|LevelName|Level $level): bool
     {
         $record = new LogRecord(
             datetime: new DateTimeImmutable($this->microsecondTimestamps, $this->timezone),
             channel: $this->name,
             message: '',
-            level: $level,
+            level: self::toMonologLevel($level),
         );
 
         foreach ($this->handlers as $handler) {
@@ -494,8 +474,8 @@ class Logger implements LoggerInterface, ResettableInterface
      */
     public function log($level, string|\Stringable $message, array $context = []): void
     {
-        if (!is_int($level) && !is_string($level)) {
-            throw new \InvalidArgumentException('$level is expected to be a string or int');
+        if (!is_string($level) && !is_int($level) && !$level instanceof Level) {
+            throw new \InvalidArgumentException('$level is expected to be a string, int or '.Level::class.' instance');
         }
 
         $level = static::toMonologLevel($level);
diff --git a/src/Monolog/Processor/GitProcessor.php b/src/Monolog/Processor/GitProcessor.php
index 920cbc3f..2cefe452 100644
--- a/src/Monolog/Processor/GitProcessor.php
+++ b/src/Monolog/Processor/GitProcessor.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Processor;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Psr\Log\LogLevel;
 use Monolog\LogRecord;
@@ -20,23 +22,19 @@ use Monolog\LogRecord;
  *
  * @author Nick Otter
  * @author Jordi Boggiano <j.boggiano@seld.be>
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class GitProcessor implements ProcessorInterface
 {
-    /** @var int */
-    private $level;
+    private Level $level;
     /** @var array{branch: string, commit: string}|array<never>|null */
     private static $cache = null;
 
     /**
-     * @param string|int $level The minimum logging level at which this Processor will be triggered
+     * @param int|string|Level|LevelName|LogLevel::* $level The minimum logging level at which this Processor will be triggered
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function __construct($level = Logger::DEBUG)
+    public function __construct(int|string|Level|LevelName $level = Level::Debug)
     {
         $this->level = Logger::toMonologLevel($level);
     }
diff --git a/src/Monolog/Processor/IntrospectionProcessor.php b/src/Monolog/Processor/IntrospectionProcessor.php
index 2cbc83b4..357bd71f 100644
--- a/src/Monolog/Processor/IntrospectionProcessor.php
+++ b/src/Monolog/Processor/IntrospectionProcessor.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Processor;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Psr\Log\LogLevel;
 use Monolog\LogRecord;
@@ -25,13 +27,10 @@ use Monolog\LogRecord;
  * triggered the FingersCrossedHandler.
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class IntrospectionProcessor implements ProcessorInterface
 {
-    private int $level;
+    private Level $level;
 
     /** @var string[] */
     private array $skipClassesPartials;
@@ -44,12 +43,12 @@ class IntrospectionProcessor implements ProcessorInterface
     ];
 
     /**
-     * @param string|int $level               The minimum logging level at which this Processor will be triggered
+     * @param string|int|Level|LevelName $level               The minimum logging level at which this Processor will be triggered
      * @param string[]   $skipClassesPartials
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function __construct($level = Logger::DEBUG, array $skipClassesPartials = [], int $skipStackFramesCount = 0)
+    public function __construct(int|string|Level|LevelName $level = Level::Debug, array $skipClassesPartials = [], int $skipStackFramesCount = 0)
     {
         $this->level = Logger::toMonologLevel($level);
         $this->skipClassesPartials = array_merge(['Monolog\\'], $skipClassesPartials);
@@ -62,7 +61,7 @@ class IntrospectionProcessor implements ProcessorInterface
     public function __invoke(LogRecord $record): LogRecord
     {
         // return if the level is not high enough
-        if ($record->level < $this->level) {
+        if ($record->level->isLowerThan($this->level)) {
             return $record;
         }
 
diff --git a/src/Monolog/Processor/MercurialProcessor.php b/src/Monolog/Processor/MercurialProcessor.php
index 7fb1340d..37222a34 100644
--- a/src/Monolog/Processor/MercurialProcessor.php
+++ b/src/Monolog/Processor/MercurialProcessor.php
@@ -11,6 +11,8 @@
 
 namespace Monolog\Processor;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Psr\Log\LogLevel;
 use Monolog\LogRecord;
@@ -19,23 +21,19 @@ use Monolog\LogRecord;
  * Injects Hg branch and Hg revision number in all records
  *
  * @author Jonathan A. Schweder <jonathanschweder@gmail.com>
- *
- * @phpstan-import-type LevelName from \Monolog\Logger
- * @phpstan-import-type Level from \Monolog\Logger
  */
 class MercurialProcessor implements ProcessorInterface
 {
-    /** @var Level */
-    private $level;
+    private Level $level;
     /** @var array{branch: string, revision: string}|array<never>|null */
     private static $cache = null;
 
     /**
-     * @param int|string $level The minimum logging level at which this Processor will be triggered
+     * @param int|string|Level|LevelName $level The minimum logging level at which this Processor will be triggered
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function __construct($level = Logger::DEBUG)
+    public function __construct(int|string|Level|LevelName $level = Level::Debug)
     {
         $this->level = Logger::toMonologLevel($level);
     }
@@ -46,7 +44,7 @@ class MercurialProcessor implements ProcessorInterface
     public function __invoke(LogRecord $record): LogRecord
     {
         // return if the level is not high enough
-        if ($record->level < $this->level) {
+        if ($record->level->isLowerThan($this->level)) {
             return $record;
         }
 
diff --git a/src/Monolog/SignalHandler.php b/src/Monolog/SignalHandler.php
index d730eea3..b9f92abd 100644
--- a/src/Monolog/SignalHandler.php
+++ b/src/Monolog/SignalHandler.php
@@ -19,9 +19,6 @@ use ReflectionExtension;
  * Monolog POSIX signal handler
  *
  * @author Robert Gust-Bardon <robert@gust-bardon.org>
- *
- * @phpstan-import-type Level from \Monolog\Logger
- * @phpstan-import-type LevelName from \Monolog\Logger
  */
 class SignalHandler
 {
@@ -30,7 +27,7 @@ class SignalHandler
 
     /** @var array<int, callable|string|int> SIG_DFL, SIG_IGN or previous callable */
     private $previousSignalHandler = [];
-    /** @var array<int, int> */
+    /** @var array<int, \Psr\Log\LogLevel::*> */
     private $signalLevelMap = [];
     /** @var array<int, bool> */
     private $signalRestartSyscalls = [];
@@ -41,21 +38,21 @@ class SignalHandler
     }
 
     /**
-     * @param  int|string $level           Level or level name
+     * @param  int|string|Level|LevelName $level           Level or level name
      * @param  bool       $callPrevious
      * @param  bool       $restartSyscalls
      * @param  bool|null  $async
      * @return $this
      *
-     * @phpstan-param Level|LevelName|LogLevel::* $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    public function registerSignalHandler(int $signo, $level = LogLevel::CRITICAL, bool $callPrevious = true, bool $restartSyscalls = true, ?bool $async = true): self
+    public function registerSignalHandler(int $signo, int|string|Level|LevelName $level = LogLevel::CRITICAL, bool $callPrevious = true, bool $restartSyscalls = true, ?bool $async = true): self
     {
         if (!extension_loaded('pcntl') || !function_exists('pcntl_signal')) {
             return $this;
         }
 
-        $level = Logger::toMonologLevel($level);
+        $level = Logger::toMonologLevel($level)->toPsrLogLevel();
 
         if ($callPrevious) {
             $handler = pcntl_signal_get_handler($signo);
diff --git a/src/Monolog/Test/TestCase.php b/src/Monolog/Test/TestCase.php
index 83981636..aa714488 100644
--- a/src/Monolog/Test/TestCase.php
+++ b/src/Monolog/Test/TestCase.php
@@ -11,17 +11,18 @@
 
 namespace Monolog\Test;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Logger;
 use Monolog\LogRecord;
 use Monolog\DateTimeImmutable;
 use Monolog\Formatter\FormatterInterface;
+use Psr\Log\LogLevel;
 
 /**
  * Lets you easily generate log records and a dummy formatter for testing purposes
  *
  * @author Jordi Boggiano <j.boggiano@seld.be>
- *
- * @phpstan-import-type Level from \Monolog\Logger
  */
 class TestCase extends \PHPUnit\Framework\TestCase
 {
@@ -29,14 +30,14 @@ class TestCase extends \PHPUnit\Framework\TestCase
      * @param array<mixed> $context
      * @param array<mixed> $extra
      *
-     * @phpstan-param  Level $level
+     * @phpstan-param value-of<Level::VALUES>|value-of<LevelName::VALUES>|Level|LevelName|LogLevel::* $level
      */
-    protected function getRecord(int $level = Logger::WARNING, string|\Stringable $message = 'test', array $context = [], string $channel = 'test', \DateTimeImmutable $datetime = new DateTimeImmutable(true), array $extra = []): LogRecord
+    protected function getRecord(int|string|LevelName|Level $level = Level::Warning, string|\Stringable $message = 'test', array $context = [], string $channel = 'test', \DateTimeImmutable $datetime = new DateTimeImmutable(true), array $extra = []): LogRecord
     {
         return new LogRecord(
             message: (string) $message,
             context: $context,
-            level: $level,
+            level: Logger::toMonologLevel($level),
             channel: $channel,
             datetime: $datetime,
             extra: $extra,
@@ -49,11 +50,11 @@ class TestCase extends \PHPUnit\Framework\TestCase
     protected function getMultipleRecords(): array
     {
         return [
-            $this->getRecord(Logger::DEBUG, 'debug message 1'),
-            $this->getRecord(Logger::DEBUG, 'debug message 2'),
-            $this->getRecord(Logger::INFO, 'information'),
-            $this->getRecord(Logger::WARNING, 'warning'),
-            $this->getRecord(Logger::ERROR, 'error'),
+            $this->getRecord(Level::Debug, 'debug message 1'),
+            $this->getRecord(Level::Debug, 'debug message 2'),
+            $this->getRecord(Level::Info, 'information'),
+            $this->getRecord(Level::Warning, 'warning'),
+            $this->getRecord(Level::Error, 'error'),
         ];
     }
 
diff --git a/tests/Monolog/ErrorHandlerTest.php b/tests/Monolog/ErrorHandlerTest.php
index 05123f2a..bc637efd 100644
--- a/tests/Monolog/ErrorHandlerTest.php
+++ b/tests/Monolog/ErrorHandlerTest.php
@@ -37,7 +37,7 @@ class ErrorHandlerTest extends \PHPUnit\Framework\TestCase
             $this->assertTrue(is_callable($prop));
             $this->assertSame($prevHandler, $prop);
 
-            $resHandler = $errHandler->registerErrorHandler([E_USER_NOTICE => Logger::EMERGENCY], false);
+            $resHandler = $errHandler->registerErrorHandler([E_USER_NOTICE => LogLevel::EMERGENCY], false);
             $this->assertSame($errHandler, $resHandler);
             trigger_error('Foo', E_USER_ERROR);
             $this->assertCount(1, $handler->getRecords());
diff --git a/tests/Monolog/Formatter/ChromePHPFormatterTest.php b/tests/Monolog/Formatter/ChromePHPFormatterTest.php
index cdfcae25..f290ba69 100644
--- a/tests/Monolog/Formatter/ChromePHPFormatterTest.php
+++ b/tests/Monolog/Formatter/ChromePHPFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class ChromePHPFormatterTest extends TestCase
@@ -23,7 +23,7 @@ class ChromePHPFormatterTest extends TestCase
     {
         $formatter = new ChromePHPFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -55,7 +55,7 @@ class ChromePHPFormatterTest extends TestCase
     {
         $formatter = new ChromePHPFormatter();
         $record = $this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -87,7 +87,7 @@ class ChromePHPFormatterTest extends TestCase
     {
         $formatter = new ChromePHPFormatter();
         $record = $this->getRecord(
-            Logger::DEBUG,
+            Level::Debug,
             'log',
             channel: 'meh',
             datetime: new \DateTimeImmutable("@0"),
@@ -114,13 +114,13 @@ class ChromePHPFormatterTest extends TestCase
         $formatter = new ChromePHPFormatter();
         $records = [
             $this->getRecord(
-                Logger::INFO,
+                Level::Info,
                 'log',
                 channel: 'meh',
                 datetime: new \DateTimeImmutable("@0"),
             ),
             $this->getRecord(
-                Logger::WARNING,
+                Level::Warning,
                 'log2',
                 channel: 'foo',
                 datetime: new \DateTimeImmutable("@0"),
diff --git a/tests/Monolog/Formatter/ElasticaFormatterTest.php b/tests/Monolog/Formatter/ElasticaFormatterTest.php
index 17d29382..64b64286 100644
--- a/tests/Monolog/Formatter/ElasticaFormatterTest.php
+++ b/tests/Monolog/Formatter/ElasticaFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 use Monolog\Test\TestCase;
 
@@ -33,7 +33,7 @@ class ElasticaFormatterTest extends TestCase
     {
         // test log message
         $msg = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['foo' => 7, 'bar', 'class' => new \stdClass],
diff --git a/tests/Monolog/Formatter/ElasticsearchFormatterTest.php b/tests/Monolog/Formatter/ElasticsearchFormatterTest.php
index 2dc89be6..438bbfd3 100644
--- a/tests/Monolog/Formatter/ElasticsearchFormatterTest.php
+++ b/tests/Monolog/Formatter/ElasticsearchFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class ElasticsearchFormatterTest extends TestCase
@@ -25,7 +25,7 @@ class ElasticsearchFormatterTest extends TestCase
     {
         // Test log message
         $msg = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['foo' => 7, 'bar', 'class' => new \stdClass],
diff --git a/tests/Monolog/Formatter/FlowdockFormatterTest.php b/tests/Monolog/Formatter/FlowdockFormatterTest.php
index 322e6ed3..1b4e8176 100644
--- a/tests/Monolog/Formatter/FlowdockFormatterTest.php
+++ b/tests/Monolog/Formatter/FlowdockFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class FlowdockFormatterTest extends TestCase
@@ -44,8 +44,8 @@ class FlowdockFormatterTest extends TestCase
     {
         $formatter = new FlowdockFormatter('test_source', 'source@test.com');
         $records = [
-            $this->getRecord(Logger::WARNING),
-            $this->getRecord(Logger::DEBUG),
+            $this->getRecord(Level::Warning),
+            $this->getRecord(Level::Debug),
         ];
         $formatted = $formatter->formatBatch($records);
 
diff --git a/tests/Monolog/Formatter/FluentdFormatterTest.php b/tests/Monolog/Formatter/FluentdFormatterTest.php
index dbebd787..318a5ca0 100644
--- a/tests/Monolog/Formatter/FluentdFormatterTest.php
+++ b/tests/Monolog/Formatter/FluentdFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class FluentdFormatterTest extends TestCase
@@ -35,7 +35,7 @@ class FluentdFormatterTest extends TestCase
      */
     public function testFormat()
     {
-        $record = $this->getRecord(Logger::WARNING, datetime: new \DateTimeImmutable("@0"));
+        $record = $this->getRecord(Level::Warning, datetime: new \DateTimeImmutable("@0"));
 
         $formatter = new FluentdFormatter();
         $this->assertEquals(
@@ -49,7 +49,7 @@ class FluentdFormatterTest extends TestCase
      */
     public function testFormatWithTag()
     {
-        $record = $this->getRecord(Logger::ERROR, datetime: new \DateTimeImmutable("@0"));
+        $record = $this->getRecord(Level::Error, datetime: new \DateTimeImmutable("@0"));
 
         $formatter = new FluentdFormatter(true);
         $this->assertEquals(
diff --git a/tests/Monolog/Formatter/GelfMessageFormatterTest.php b/tests/Monolog/Formatter/GelfMessageFormatterTest.php
index fd1adb7d..b33687a6 100644
--- a/tests/Monolog/Formatter/GelfMessageFormatterTest.php
+++ b/tests/Monolog/Formatter/GelfMessageFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class GelfMessageFormatterTest extends TestCase
@@ -30,7 +30,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             datetime: new \DateTimeImmutable("@0"),
@@ -62,7 +62,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -84,7 +84,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -120,7 +120,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger', 'exception' => [
@@ -146,7 +146,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -179,7 +179,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['exception' => str_repeat(' ', 32767)],
@@ -205,7 +205,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter('LONG_SYSTEM_NAME', null, 'ctxt_', PHP_INT_MAX);
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['exception' => str_repeat(' ', 32767 * 2)],
@@ -231,7 +231,7 @@ class GelfMessageFormatterTest extends TestCase
     {
         $formatter = new GelfMessageFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             str_repeat('в', 32767),
             channel: 'meh',
             context: ['exception' => str_repeat('а', 32767)],
diff --git a/tests/Monolog/Formatter/JsonFormatterTest.php b/tests/Monolog/Formatter/JsonFormatterTest.php
index 38fd66c8..cab71f93 100644
--- a/tests/Monolog/Formatter/JsonFormatterTest.php
+++ b/tests/Monolog/Formatter/JsonFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 use Monolog\Test\TestCase;
 
@@ -85,8 +85,8 @@ class JsonFormatterTest extends TestCase
     {
         $formatter = new JsonFormatter();
         $records = [
-            $this->getRecord(Logger::WARNING),
-            $this->getRecord(Logger::DEBUG),
+            $this->getRecord(Level::Warning),
+            $this->getRecord(Level::Debug),
         ];
         $this->assertEquals(json_encode($records), $formatter->formatBatch($records));
     }
@@ -99,8 +99,8 @@ class JsonFormatterTest extends TestCase
     {
         $formatter = new JsonFormatter(JsonFormatter::BATCH_MODE_NEWLINES);
         $records = [
-            $this->getRecord(Logger::WARNING),
-            $this->getRecord(Logger::DEBUG),
+            $this->getRecord(Level::Warning),
+            $this->getRecord(Level::Debug),
         ];
         $expected = array_map(fn (LogRecord $record) => json_encode($record->toArray(), JSON_FORCE_OBJECT), $records);
         $this->assertEquals(implode("\n", $expected), $formatter->formatBatch($records));
@@ -213,7 +213,7 @@ class JsonFormatterTest extends TestCase
     private function formatRecordWithExceptionInContext(JsonFormatter $formatter, \Throwable $exception)
     {
         $message = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'foobar',
             channel: 'core',
             context: ['exception' => $exception],
@@ -262,7 +262,7 @@ class JsonFormatterTest extends TestCase
         $largeArray = range(1, 1000);
 
         $res = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'bar',
             channel: 'test',
             context: array($largeArray),
@@ -278,7 +278,7 @@ class JsonFormatterTest extends TestCase
         $largeArray = range(1, 2000);
 
         $res = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'bar',
             channel: 'test',
             context: array($largeArray),
@@ -293,7 +293,7 @@ class JsonFormatterTest extends TestCase
         $formatter = new JsonFormatter(JsonFormatter::BATCH_MODE_JSON, true, true);
 
         $record = $formatter->format($this->getRecord(
-            Logger::DEBUG,
+            Level::Debug,
             'Testing',
             channel: 'test',
             datetime: new \DateTimeImmutable('2022-02-22 00:00:00'),
diff --git a/tests/Monolog/Formatter/LineFormatterTest.php b/tests/Monolog/Formatter/LineFormatterTest.php
index f3128a77..0cc5d246 100644
--- a/tests/Monolog/Formatter/LineFormatterTest.php
+++ b/tests/Monolog/Formatter/LineFormatterTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Formatter;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @covers Monolog\Formatter\LineFormatter
@@ -23,7 +23,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter(null, 'Y-m-d');
         $message = $formatter->format($this->getRecord(
-            Logger::WARNING,
+            Level::Warning,
             'foo',
             channel: 'log',
         ));
@@ -34,7 +34,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter(null, 'Y-m-d');
         $message = $formatter->format($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'foo',
             channel: 'meh',
             context: [
@@ -51,7 +51,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter(null, 'Y-m-d');
         $message = $formatter->format($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             extra: ['ip' => '127.0.0.1'],
@@ -63,7 +63,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter("[%datetime%] %channel%.%level_name%: %message% %context% %extra.file% %extra%\n", 'Y-m-d');
         $message = $formatter->format($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             extra: ['ip' => '127.0.0.1', 'file' => 'test'],
@@ -75,7 +75,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter(null, 'Y-m-d', false, true);
         $message = $formatter->format($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
         ));
@@ -86,7 +86,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter('%context.foo% => %extra.foo%');
         $message = $formatter->format($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['foo' => 'bar'],
@@ -100,7 +100,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter(null, 'Y-m-d');
         $message = $formatter->format($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'foobar',
             channel: 'meh',
             context: [],
@@ -114,7 +114,7 @@ class LineFormatterTest extends TestCase
     {
         $formatter = new LineFormatter(null, 'Y-m-d');
         $message = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'foobar',
             channel: 'core',
             context: ['exception' => new \RuntimeException('Foo')],
@@ -130,7 +130,7 @@ class LineFormatterTest extends TestCase
         $formatter = new LineFormatter(null, 'Y-m-d');
         $formatter->includeStacktraces();
         $message = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'foobar',
             channel: 'core',
             context: ['exception' => new \RuntimeException('Foo')],
@@ -146,7 +146,7 @@ class LineFormatterTest extends TestCase
         $formatter = new LineFormatter(null, 'Y-m-d');
         $previous = new \LogicException('Wut?');
         $message = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'foobar',
             channel: 'core',
             context: ['exception' => new \RuntimeException('Foo', 0, $previous)],
@@ -165,7 +165,7 @@ class LineFormatterTest extends TestCase
 
         $formatter = new LineFormatter(null, 'Y-m-d');
         $message = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'foobar',
             channel: 'core',
             context: ['exception' => new \SoapFault('foo', 'bar', 'hello', 'world')],
@@ -176,7 +176,7 @@ class LineFormatterTest extends TestCase
         $this->assertEquals('['.date('Y-m-d').'] core.CRITICAL: foobar {"exception":"[object] (SoapFault(code: 0 faultcode: foo faultactor: hello detail: world): bar at '.substr($path, 1, -1).':'.(__LINE__ - 5).')"} []'."\n", $message);
 
         $message = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'foobar',
             channel: 'core',
             context: ['exception' => new \SoapFault('foo', 'bar', 'hello', (object) ['bar' => (object) ['biz' => 'baz'], 'foo' => 'world'])],
@@ -192,12 +192,12 @@ class LineFormatterTest extends TestCase
         $formatter = new LineFormatter(null, 'Y-m-d');
         $message = $formatter->formatBatch([
             $this->getRecord(
-                Logger::CRITICAL,
+                Level::Critical,
                 'bar',
                 channel: 'test',
             ),
             $this->getRecord(
-                Logger::WARNING,
+                Level::Warning,
                 'foo',
                 channel: 'log',
             ),
diff --git a/tests/Monolog/Formatter/LogstashFormatterTest.php b/tests/Monolog/Formatter/LogstashFormatterTest.php
index f2d13422..81683e73 100644
--- a/tests/Monolog/Formatter/LogstashFormatterTest.php
+++ b/tests/Monolog/Formatter/LogstashFormatterTest.php
@@ -11,7 +11,8 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Test\TestCase;
 
 class LogstashFormatterTest extends TestCase
@@ -23,7 +24,7 @@ class LogstashFormatterTest extends TestCase
     {
         $formatter = new LogstashFormatter('test', 'hostname');
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             datetime: new \DateTimeImmutable("@0"),
@@ -35,8 +36,8 @@ class LogstashFormatterTest extends TestCase
         $this->assertEquals("1", $message['@version']);
         $this->assertEquals('log', $message['message']);
         $this->assertEquals('meh', $message['channel']);
-        $this->assertEquals('ERROR', $message['level']);
-        $this->assertEquals(Logger::ERROR, $message['monolog_level']);
+        $this->assertEquals(LevelName::Error->value, $message['level']);
+        $this->assertEquals(Level::Error->value, $message['monolog_level']);
         $this->assertEquals('test', $message['type']);
         $this->assertEquals('hostname', $message['host']);
 
@@ -54,7 +55,7 @@ class LogstashFormatterTest extends TestCase
     {
         $formatter = new LogstashFormatter('test');
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -75,7 +76,7 @@ class LogstashFormatterTest extends TestCase
     {
         $formatter = new LogstashFormatter('test');
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -105,7 +106,7 @@ class LogstashFormatterTest extends TestCase
     {
         $formatter = new LogstashFormatter('test');
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -132,7 +133,7 @@ class LogstashFormatterTest extends TestCase
     {
         $formatter = new LogstashFormatter('app', 'test');
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -150,7 +151,7 @@ class LogstashFormatterTest extends TestCase
     {
         $formatter = new LogstashFormatter('test', 'hostname');
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: '¯\_(ツ)_/¯',
             datetime: new \DateTimeImmutable("@0"),
diff --git a/tests/Monolog/Formatter/MongoDBFormatterTest.php b/tests/Monolog/Formatter/MongoDBFormatterTest.php
index 4874755f..73d7ea99 100644
--- a/tests/Monolog/Formatter/MongoDBFormatterTest.php
+++ b/tests/Monolog/Formatter/MongoDBFormatterTest.php
@@ -14,7 +14,8 @@ namespace Monolog\Formatter;
 use MongoDB\BSON\ObjectId;
 use MongoDB\BSON\Regex;
 use MongoDB\BSON\UTCDateTime;
-use Monolog\Logger;
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Test\TestCase;
 
 /**
@@ -62,7 +63,7 @@ class MongoDBFormatterTest extends TestCase
     {
         $record = $this->getRecord(
             message: 'some log message',
-            level: Logger::WARNING,
+            level: Level::Warning,
             channel: 'test',
             datetime: new \DateTimeImmutable('2016-01-21T21:11:30.123456+00:00'),
         );
@@ -73,8 +74,8 @@ class MongoDBFormatterTest extends TestCase
         $this->assertCount(7, $formattedRecord);
         $this->assertEquals('some log message', $formattedRecord['message']);
         $this->assertEquals([], $formattedRecord['context']);
-        $this->assertEquals(Logger::WARNING, $formattedRecord['level']);
-        $this->assertEquals(Logger::getLevelName(Logger::WARNING), $formattedRecord['level_name']);
+        $this->assertEquals(Level::Warning->value, $formattedRecord['level']);
+        $this->assertEquals(LevelName::Warning->value, $formattedRecord['level_name']);
         $this->assertEquals('test', $formattedRecord['channel']);
         $this->assertInstanceOf('MongoDB\BSON\UTCDateTime', $formattedRecord['datetime']);
         $this->assertEquals('1453410690123', $formattedRecord['datetime']->__toString());
@@ -96,7 +97,7 @@ class MongoDBFormatterTest extends TestCase
                 'context_int' => 123456,
                 'except' => new \Exception('exception message', 987),
             ],
-            level: Logger::WARNING,
+            level: Level::Warning,
             channel: 'test',
             datetime: new \DateTimeImmutable('2016-01-21T21:11:30.213000+00:00'),
         );
@@ -140,7 +141,7 @@ class MongoDBFormatterTest extends TestCase
                     ],
                 ],
             ],
-            level: Logger::WARNING,
+            level: Level::Warning,
             channel: 'test',
             datetime: new \DateTimeImmutable('2016-01-21T21:11:30.123456+00:00'),
         );
@@ -174,7 +175,7 @@ class MongoDBFormatterTest extends TestCase
                     ],
                 ],
             ],
-            level: Logger::WARNING,
+            level: Level::Warning,
             channel: 'test',
             datetime: new \DateTimeImmutable('2016-01-21T21:11:30.123456+00:00'),
         );
@@ -211,7 +212,7 @@ class MongoDBFormatterTest extends TestCase
             context: [
                 'nest2' => $someObject,
             ],
-            level: Logger::WARNING,
+            level: Level::Warning,
             channel: 'test',
             datetime: new \DateTimeImmutable('2016-01-21T21:11:30.123456+00:00'),
         );
@@ -238,7 +239,7 @@ class MongoDBFormatterTest extends TestCase
             context: [
                 'nest2' => new \Exception('exception message', 987),
             ],
-            level: Logger::WARNING,
+            level: Level::Warning,
             channel: 'test',
             datetime: new \DateTimeImmutable('2016-01-21T21:11:30.123456+00:00'),
         );
@@ -262,7 +263,7 @@ class MongoDBFormatterTest extends TestCase
                     'regex' => new Regex('pattern'),
                 ],
             ],
-            level: Logger::WARNING,
+            level: Level::Warning,
             channel: 'test',
             datetime: new \DateTimeImmutable('2016-01-21T21:11:30.123456+00:00'),
         );
diff --git a/tests/Monolog/Formatter/NormalizerFormatterTest.php b/tests/Monolog/Formatter/NormalizerFormatterTest.php
index ab8d7b17..e13bb2ce 100644
--- a/tests/Monolog/Formatter/NormalizerFormatterTest.php
+++ b/tests/Monolog/Formatter/NormalizerFormatterTest.php
@@ -11,8 +11,9 @@
 
 namespace Monolog\Formatter;
 
+use Monolog\LevelName;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @covers Monolog\Formatter\NormalizerFormatter
@@ -23,7 +24,7 @@ class NormalizerFormatterTest extends TestCase
     {
         $formatter = new NormalizerFormatter('Y-m-d');
         $formatted = $formatter->format($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'foo',
             channel: 'meh',
             extra: ['foo' => new TestFooNorm, 'bar' => new TestBarNorm, 'baz' => [], 'res' => fopen('php://memory', 'rb')],
@@ -37,8 +38,8 @@ class NormalizerFormatterTest extends TestCase
         ));
 
         $this->assertEquals([
-            'level_name' => 'ERROR',
-            'level' => Logger::ERROR,
+            'level_name' => LevelName::Error->value,
+            'level' => Level::Error->value,
             'channel' => 'meh',
             'message' => 'foo',
             'datetime' => date('Y-m-d'),
@@ -142,13 +143,13 @@ class NormalizerFormatterTest extends TestCase
     {
         $formatter = new NormalizerFormatter('Y-m-d');
         $formatted = $formatter->formatBatch([
-            $this->getRecord(Logger::CRITICAL, 'bar', channel: 'test'),
-            $this->getRecord(Logger::WARNING, 'foo', channel: 'log'),
+            $this->getRecord(Level::Critical, 'bar', channel: 'test'),
+            $this->getRecord(Level::Warning, 'foo', channel: 'log'),
         ]);
         $this->assertEquals([
             [
-                'level_name' => 'CRITICAL',
-                'level' => Logger::CRITICAL,
+                'level_name' => LevelName::Critical->value,
+                'level' => Level::Critical->value,
                 'channel' => 'test',
                 'message' => 'bar',
                 'context' => [],
@@ -156,8 +157,8 @@ class NormalizerFormatterTest extends TestCase
                 'extra' => [],
             ],
             [
-                'level_name' => 'WARNING',
-                'level' => Logger::WARNING,
+                'level_name' => LevelName::Warning->value,
+                'level' => Level::Warning->value,
                 'channel' => 'log',
                 'message' => 'foo',
                 'context' => [],
@@ -241,7 +242,7 @@ class NormalizerFormatterTest extends TestCase
         $largeArray = range(1, 1000);
 
         $res = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'bar',
             channel: 'test',
             context: [$largeArray],
@@ -257,7 +258,7 @@ class NormalizerFormatterTest extends TestCase
         $largeArray = range(1, 2000);
 
         $res = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'bar',
             channel: 'test',
             context: [$largeArray],
@@ -379,7 +380,7 @@ class NormalizerFormatterTest extends TestCase
     private function formatRecordWithExceptionInContext(NormalizerFormatter $formatter, \Throwable $exception)
     {
         $message = $formatter->format($this->getRecord(
-            Logger::CRITICAL,
+            Level::Critical,
             'foobar',
             channel: 'core',
             context: ['exception' => $exception],
diff --git a/tests/Monolog/Formatter/WildfireFormatterTest.php b/tests/Monolog/Formatter/WildfireFormatterTest.php
index a3babee0..06a0fa70 100644
--- a/tests/Monolog/Formatter/WildfireFormatterTest.php
+++ b/tests/Monolog/Formatter/WildfireFormatterTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Formatter;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class WildfireFormatterTest extends TestCase
@@ -23,7 +23,7 @@ class WildfireFormatterTest extends TestCase
     {
         $wildfire = new WildfireFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -46,7 +46,7 @@ class WildfireFormatterTest extends TestCase
     {
         $wildfire = new WildfireFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
             context: ['from' => 'logger'],
@@ -69,7 +69,7 @@ class WildfireFormatterTest extends TestCase
     {
         $wildfire = new WildfireFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
         );
@@ -91,7 +91,7 @@ class WildfireFormatterTest extends TestCase
 
         $wildfire = new WildfireFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log',
             channel: 'meh',
         );
@@ -106,7 +106,7 @@ class WildfireFormatterTest extends TestCase
     {
         $wildfire = new WildfireFormatter();
         $record = $this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'table-message',
             channel: 'table-channel',
             context: [
diff --git a/tests/Monolog/Handler/AbstractHandlerTest.php b/tests/Monolog/Handler/AbstractHandlerTest.php
index b7451a73..58de1dd9 100644
--- a/tests/Monolog/Handler/AbstractHandlerTest.php
+++ b/tests/Monolog/Handler/AbstractHandlerTest.php
@@ -11,8 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
 
 class AbstractHandlerTest extends TestCase
 {
@@ -25,13 +25,13 @@ class AbstractHandlerTest extends TestCase
      */
     public function testConstructAndGetSet()
     {
-        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractHandler', [Logger::WARNING, false]);
-        $this->assertEquals(Logger::WARNING, $handler->getLevel());
+        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractHandler', [Level::Warning, false]);
+        $this->assertEquals(Level::Warning, $handler->getLevel());
         $this->assertEquals(false, $handler->getBubble());
 
-        $handler->setLevel(Logger::ERROR);
+        $handler->setLevel(Level::Error);
         $handler->setBubble(true);
-        $this->assertEquals(Logger::ERROR, $handler->getLevel());
+        $this->assertEquals(Level::Error, $handler->getLevel());
         $this->assertEquals(true, $handler->getBubble());
     }
 
@@ -51,9 +51,9 @@ class AbstractHandlerTest extends TestCase
      */
     public function testIsHandling()
     {
-        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractHandler', [Logger::WARNING, false]);
+        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractHandler', [Level::Warning, false]);
         $this->assertTrue($handler->isHandling($this->getRecord()));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::DEBUG)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Debug)));
     }
 
     /**
@@ -62,8 +62,8 @@ class AbstractHandlerTest extends TestCase
     public function testHandlesPsrStyleLevels()
     {
         $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractHandler', ['warning', false]);
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::DEBUG)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Debug)));
         $handler->setLevel('debug');
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::DEBUG)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Debug)));
     }
 }
diff --git a/tests/Monolog/Handler/AbstractProcessingHandlerTest.php b/tests/Monolog/Handler/AbstractProcessingHandlerTest.php
index 7d732b39..6fc3c38b 100644
--- a/tests/Monolog/Handler/AbstractProcessingHandlerTest.php
+++ b/tests/Monolog/Handler/AbstractProcessingHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Processor\WebProcessor;
 use Monolog\Formatter\LineFormatter;
 
@@ -24,7 +24,7 @@ class AbstractProcessingHandlerTest extends TestCase
      */
     public function testConstructAndGetSet()
     {
-        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Logger::WARNING, false]);
+        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Level::Warning, false]);
         $handler->setFormatter($formatter = new LineFormatter);
         $this->assertSame($formatter, $handler->getFormatter());
     }
@@ -34,8 +34,8 @@ class AbstractProcessingHandlerTest extends TestCase
      */
     public function testHandleLowerLevelMessage()
     {
-        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Logger::WARNING, true]);
-        $this->assertFalse($handler->handle($this->getRecord(Logger::DEBUG)));
+        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Level::Warning, true]);
+        $this->assertFalse($handler->handle($this->getRecord(Level::Debug)));
     }
 
     /**
@@ -43,7 +43,7 @@ class AbstractProcessingHandlerTest extends TestCase
      */
     public function testHandleBubbling()
     {
-        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Logger::DEBUG, true]);
+        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Level::Debug, true]);
         $this->assertFalse($handler->handle($this->getRecord()));
     }
 
@@ -52,7 +52,7 @@ class AbstractProcessingHandlerTest extends TestCase
      */
     public function testHandleNotBubbling()
     {
-        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Logger::DEBUG, false]);
+        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Level::Debug, false]);
         $this->assertTrue($handler->handle($this->getRecord()));
     }
 
@@ -61,9 +61,9 @@ class AbstractProcessingHandlerTest extends TestCase
      */
     public function testHandleIsFalseWhenNotHandled()
     {
-        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Logger::WARNING, false]);
+        $handler = $this->getMockForAbstractClass('Monolog\Handler\AbstractProcessingHandler', [Level::Warning, false]);
         $this->assertTrue($handler->handle($this->getRecord()));
-        $this->assertFalse($handler->handle($this->getRecord(Logger::DEBUG)));
+        $this->assertFalse($handler->handle($this->getRecord(Level::Debug)));
     }
 
     /**
diff --git a/tests/Monolog/Handler/AmqpHandlerTest.php b/tests/Monolog/Handler/AmqpHandlerTest.php
index c2de874c..32172705 100644
--- a/tests/Monolog/Handler/AmqpHandlerTest.php
+++ b/tests/Monolog/Handler/AmqpHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use PhpAmqpLib\Message\AMQPMessage;
 
 /**
@@ -46,7 +46,7 @@ class AmqpHandlerTest extends TestCase
 
         $handler = new AmqpHandler($exchange);
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
         $expected = [
             [
@@ -103,7 +103,7 @@ class AmqpHandlerTest extends TestCase
 
         $handler = new AmqpHandler($exchange, 'log');
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
         $expected = [
             [
diff --git a/tests/Monolog/Handler/BrowserConsoleHandlerTest.php b/tests/Monolog/Handler/BrowserConsoleHandlerTest.php
index 5bda6b00..1628a4b6 100644
--- a/tests/Monolog/Handler/BrowserConsoleHandlerTest.php
+++ b/tests/Monolog/Handler/BrowserConsoleHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @covers Monolog\Handler\BrowserConsoleHandlerTest
@@ -37,7 +37,7 @@ class BrowserConsoleHandlerTest extends TestCase
         $handler = new BrowserConsoleHandler();
         $handler->setFormatter($this->getIdentityFormatter());
 
-        $handler->handle($this->getRecord(Logger::DEBUG, 'foo[[bar]]{color: red}'));
+        $handler->handle($this->getRecord(Level::Debug, 'foo[[bar]]{color: red}'));
 
         $expected = <<<EOF
 (function (c) {if (c && c.groupCollapsed) {
@@ -53,7 +53,7 @@ EOF;
         $handler = new BrowserConsoleHandler();
         $handler->setFormatter($this->getIdentityFormatter());
 
-        $handler->handle($this->getRecord(Logger::DEBUG, 'foo[[bar]]{color: red}[[baz]]{color: blue}'));
+        $handler->handle($this->getRecord(Level::Debug, 'foo[[bar]]{color: red}[[baz]]{color: blue}'));
 
         $expected = <<<EOF
 (function (c) {if (c && c.groupCollapsed) {
@@ -69,7 +69,7 @@ EOF;
         $handler = new BrowserConsoleHandler();
         $handler->setFormatter($this->getIdentityFormatter());
 
-        $handler->handle($this->getRecord(Logger::DEBUG, "[foo] [[\"bar\n[baz]\"]]{color: red}"));
+        $handler->handle($this->getRecord(Level::Debug, "[foo] [[\"bar\n[baz]\"]]{color: red}"));
 
         $expected = <<<EOF
 (function (c) {if (c && c.groupCollapsed) {
@@ -85,9 +85,9 @@ EOF;
         $handler = new BrowserConsoleHandler();
         $handler->setFormatter($this->getIdentityFormatter());
 
-        $handler->handle($this->getRecord(Logger::DEBUG, '[[foo]]{macro: autolabel}'));
-        $handler->handle($this->getRecord(Logger::DEBUG, '[[bar]]{macro: autolabel}'));
-        $handler->handle($this->getRecord(Logger::DEBUG, '[[foo]]{macro: autolabel}'));
+        $handler->handle($this->getRecord(Level::Debug, '[[foo]]{macro: autolabel}'));
+        $handler->handle($this->getRecord(Level::Debug, '[[bar]]{macro: autolabel}'));
+        $handler->handle($this->getRecord(Level::Debug, '[[foo]]{macro: autolabel}'));
 
         $expected = <<<EOF
 (function (c) {if (c && c.groupCollapsed) {
@@ -105,7 +105,7 @@ EOF;
         $handler = new BrowserConsoleHandler();
         $handler->setFormatter($this->getIdentityFormatter());
 
-        $handler->handle($this->getRecord(Logger::DEBUG, 'test', ['foo' => 'bar', 0 => 'oop']));
+        $handler->handle($this->getRecord(Level::Debug, 'test', ['foo' => 'bar', 0 => 'oop']));
 
         $expected = <<<EOF
 (function (c) {if (c && c.groupCollapsed) {
@@ -128,10 +128,10 @@ EOF;
         $handler2 = new BrowserConsoleHandler();
         $handler2->setFormatter($this->getIdentityFormatter());
 
-        $handler1->handle($this->getRecord(Logger::DEBUG, 'test1'));
-        $handler2->handle($this->getRecord(Logger::DEBUG, 'test2'));
-        $handler1->handle($this->getRecord(Logger::DEBUG, 'test3'));
-        $handler2->handle($this->getRecord(Logger::DEBUG, 'test4'));
+        $handler1->handle($this->getRecord(Level::Debug, 'test1'));
+        $handler2->handle($this->getRecord(Level::Debug, 'test2'));
+        $handler1->handle($this->getRecord(Level::Debug, 'test3'));
+        $handler2->handle($this->getRecord(Level::Debug, 'test4'));
 
         $expected = <<<EOF
 (function (c) {if (c && c.groupCollapsed) {
diff --git a/tests/Monolog/Handler/BufferHandlerTest.php b/tests/Monolog/Handler/BufferHandlerTest.php
index 15c77b38..8e709612 100644
--- a/tests/Monolog/Handler/BufferHandlerTest.php
+++ b/tests/Monolog/Handler/BufferHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class BufferHandlerTest extends TestCase
 {
@@ -27,8 +27,8 @@ class BufferHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new BufferHandler($test);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertFalse($test->hasDebugRecords());
         $this->assertFalse($test->hasInfoRecords());
         $handler->close();
@@ -44,8 +44,8 @@ class BufferHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new BufferHandler($test);
-        $handler->handle($this->getRecord(Logger::WARNING));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Warning));
+        $handler->handle($this->getRecord(Level::Debug));
         $this->shutdownCheckHandler = $test;
         register_shutdown_function([$this, 'checkPropagation']);
     }
@@ -65,10 +65,10 @@ class BufferHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new BufferHandler($test, 2);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
+        $handler->handle($this->getRecord(Level::Warning));
         $handler->close();
         $this->assertTrue($test->hasWarningRecords());
         $this->assertTrue($test->hasInfoRecords());
@@ -81,22 +81,22 @@ class BufferHandlerTest extends TestCase
     public function testHandleBufferLimitWithFlushOnOverflow()
     {
         $test = new TestHandler();
-        $handler = new BufferHandler($test, 3, Logger::DEBUG, true, true);
+        $handler = new BufferHandler($test, 3, Level::Debug, true, true);
 
         // send two records
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Debug));
         $this->assertFalse($test->hasDebugRecords());
         $this->assertCount(0, $test->getRecords());
 
         // overflow
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertTrue($test->hasDebugRecords());
         $this->assertCount(3, $test->getRecords());
 
         // should buffer again
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertCount(3, $test->getRecords());
 
         $handler->close();
@@ -111,11 +111,11 @@ class BufferHandlerTest extends TestCase
     public function testHandleLevel()
     {
         $test = new TestHandler();
-        $handler = new BufferHandler($test, 0, Logger::INFO);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
-        $handler->handle($this->getRecord(Logger::WARNING));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler = new BufferHandler($test, 0, Level::Info);
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
+        $handler->handle($this->getRecord(Level::Warning));
+        $handler->handle($this->getRecord(Level::Debug));
         $handler->close();
         $this->assertTrue($test->hasWarningRecords());
         $this->assertTrue($test->hasInfoRecords());
@@ -129,8 +129,8 @@ class BufferHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new BufferHandler($test, 0);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         $handler->flush();
         $this->assertTrue($test->hasInfoRecords());
         $this->assertTrue($test->hasDebugRecords());
@@ -149,7 +149,7 @@ class BufferHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $handler->flush();
         $this->assertTrue($test->hasWarningRecords());
         $records = $test->getRecords();
diff --git a/tests/Monolog/Handler/ChromePHPHandlerTest.php b/tests/Monolog/Handler/ChromePHPHandlerTest.php
index 1ee58195..5600cd28 100644
--- a/tests/Monolog/Handler/ChromePHPHandlerTest.php
+++ b/tests/Monolog/Handler/ChromePHPHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @covers Monolog\Handler\ChromePHPHandler
@@ -34,8 +34,8 @@ class ChromePHPHandlerTest extends TestCase
 
         $handler = new TestChromePHPHandler();
         $handler->setFormatter($this->getIdentityFormatter());
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Warning));
 
         $expected = [
             'X-ChromeLogger-Data'   => base64_encode(utf8_encode(json_encode([
@@ -65,11 +65,11 @@ class ChromePHPHandlerTest extends TestCase
     public function testHeadersOverflow()
     {
         $handler = new TestChromePHPHandler();
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::WARNING, str_repeat('a', 2 * 1024)));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Warning, str_repeat('a', 2 * 1024)));
 
         // overflow chrome headers limit
-        $handler->handle($this->getRecord(Logger::WARNING, str_repeat('b', 2 * 1024)));
+        $handler->handle($this->getRecord(Level::Warning, str_repeat('b', 2 * 1024)));
 
         $expected = [
             'X-ChromeLogger-Data'   => base64_encode(utf8_encode(json_encode([
@@ -106,13 +106,13 @@ class ChromePHPHandlerTest extends TestCase
     {
         $handler = new TestChromePHPHandler();
         $handler->setFormatter($this->getIdentityFormatter());
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Warning));
 
         $handler2 = new TestChromePHPHandler();
         $handler2->setFormatter($this->getIdentityFormatter());
-        $handler2->handle($this->getRecord(Logger::DEBUG));
-        $handler2->handle($this->getRecord(Logger::WARNING));
+        $handler2->handle($this->getRecord(Level::Debug));
+        $handler2->handle($this->getRecord(Level::Warning));
 
         $expected = [
             'X-ChromeLogger-Data'   => base64_encode(utf8_encode(json_encode([
diff --git a/tests/Monolog/Handler/CouchDBHandlerTest.php b/tests/Monolog/Handler/CouchDBHandlerTest.php
index f89a130b..289bcf5a 100644
--- a/tests/Monolog/Handler/CouchDBHandlerTest.php
+++ b/tests/Monolog/Handler/CouchDBHandlerTest.php
@@ -12,13 +12,13 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class CouchDBHandlerTest extends TestCase
 {
     public function testHandle()
     {
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
         $handler = new CouchDBHandler();
 
diff --git a/tests/Monolog/Handler/DeduplicationHandlerTest.php b/tests/Monolog/Handler/DeduplicationHandlerTest.php
index 86c7c8a5..f617e019 100644
--- a/tests/Monolog/Handler/DeduplicationHandlerTest.php
+++ b/tests/Monolog/Handler/DeduplicationHandlerTest.php
@@ -11,8 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
 
 class DeduplicationHandlerTest extends TestCase
 {
@@ -23,10 +23,10 @@ class DeduplicationHandlerTest extends TestCase
     {
         $test = new TestHandler();
         @unlink(sys_get_temp_dir().'/monolog_dedup.log');
-        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', 0);
+        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', Level::Debug);
 
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
 
         $handler->flush();
 
@@ -43,10 +43,10 @@ class DeduplicationHandlerTest extends TestCase
     {
         $test = new TestHandler();
         @unlink(sys_get_temp_dir().'/monolog_dedup.log');
-        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', 0);
+        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', Level::Debug);
 
-        $handler->handle($this->getRecord(Logger::ERROR, 'Foo:bar'));
-        $handler->handle($this->getRecord(Logger::CRITICAL, "Foo\nbar"));
+        $handler->handle($this->getRecord(Level::Error, 'Foo:bar'));
+        $handler->handle($this->getRecord(Level::Critical, "Foo\nbar"));
 
         $handler->flush();
 
@@ -64,10 +64,10 @@ class DeduplicationHandlerTest extends TestCase
     public function testFlushSkipsIfLogExists()
     {
         $test = new TestHandler();
-        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', 0);
+        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', Level::Debug);
 
-        $handler->handle($this->getRecord(Logger::ERROR, 'Foo:bar'));
-        $handler->handle($this->getRecord(Logger::CRITICAL, "Foo\nbar"));
+        $handler->handle($this->getRecord(Level::Error, 'Foo:bar'));
+        $handler->handle($this->getRecord(Level::Critical, "Foo\nbar"));
 
         $handler->flush();
 
@@ -85,11 +85,11 @@ class DeduplicationHandlerTest extends TestCase
     public function testFlushPassthruIfLogTooOld()
     {
         $test = new TestHandler();
-        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', 0);
+        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', Level::Debug);
 
-        $record = $this->getRecord(Logger::ERROR, datetime: new \DateTimeImmutable('+62seconds'));
+        $record = $this->getRecord(Level::Error, datetime: new \DateTimeImmutable('+62seconds'));
         $handler->handle($record);
-        $record = $this->getRecord(Logger::CRITICAL, datetime: new \DateTimeImmutable('+62seconds'));
+        $record = $this->getRecord(Level::Critical, datetime: new \DateTimeImmutable('+62seconds'));
         $handler->handle($record);
 
         $handler->flush();
@@ -109,14 +109,14 @@ class DeduplicationHandlerTest extends TestCase
     {
         $test = new TestHandler();
         @unlink(sys_get_temp_dir().'/monolog_dedup.log');
-        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', 0);
+        $handler = new DeduplicationHandler($test, sys_get_temp_dir().'/monolog_dedup.log', Level::Debug);
 
         // handle two records from yesterday, and one recent
-        $record = $this->getRecord(Logger::ERROR, datetime: new \DateTimeImmutable('-1day -10seconds'));
+        $record = $this->getRecord(Level::Error, datetime: new \DateTimeImmutable('-1day -10seconds'));
         $handler->handle($record);
-        $record2 = $this->getRecord(Logger::CRITICAL, datetime: new \DateTimeImmutable('-1day -10seconds'));
+        $record2 = $this->getRecord(Level::Critical, datetime: new \DateTimeImmutable('-1day -10seconds'));
         $handler->handle($record2);
-        $record3 = $this->getRecord(Logger::CRITICAL, datetime: new \DateTimeImmutable('-30seconds'));
+        $record3 = $this->getRecord(Level::Critical, datetime: new \DateTimeImmutable('-30seconds'));
         $handler->handle($record3);
 
         // log is written as none of them are duplicate
@@ -137,8 +137,8 @@ class DeduplicationHandlerTest extends TestCase
         $this->assertFalse($test->hasCriticalRecords());
 
         // log new records, duplicate log gets GC'd at the end of this flush call
-        $handler->handle($record = $this->getRecord(Logger::ERROR));
-        $handler->handle($record2 = $this->getRecord(Logger::CRITICAL));
+        $handler->handle($record = $this->getRecord(Level::Error));
+        $handler->handle($record2 = $this->getRecord(Level::Critical));
         $handler->flush();
 
         // log should now contain the new errors and the previous one that was recent enough
diff --git a/tests/Monolog/Handler/DoctrineCouchDBHandlerTest.php b/tests/Monolog/Handler/DoctrineCouchDBHandlerTest.php
index 35330681..1f6f2ffb 100644
--- a/tests/Monolog/Handler/DoctrineCouchDBHandlerTest.php
+++ b/tests/Monolog/Handler/DoctrineCouchDBHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class DoctrineCouchDBHandlerTest extends TestCase
 {
@@ -30,12 +30,12 @@ class DoctrineCouchDBHandlerTest extends TestCase
             ->disableOriginalConstructor()
             ->getMock();
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
         $expected = [
             'message' => 'test',
             'context' => ['data' => ['stdClass' => []], 'foo' => 34],
-            'level' => Logger::WARNING,
+            'level' => Level::Warning->value,
             'level_name' => 'WARNING',
             'channel' => 'test',
             'datetime' => (string) $record->datetime,
diff --git a/tests/Monolog/Handler/ElasticaHandlerTest.php b/tests/Monolog/Handler/ElasticaHandlerTest.php
index 1fa3be3b..706e417f 100644
--- a/tests/Monolog/Handler/ElasticaHandlerTest.php
+++ b/tests/Monolog/Handler/ElasticaHandlerTest.php
@@ -14,7 +14,7 @@ namespace Monolog\Handler;
 use Monolog\Formatter\ElasticaFormatter;
 use Monolog\Formatter\NormalizerFormatter;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\LogRecord;
 use Elastica\Client;
 use Elastica\Request;
@@ -58,7 +58,7 @@ class ElasticaHandlerTest extends TestCase
     public function testHandle()
     {
         // log message
-        $msg = $this->getRecord(Logger::ERROR, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
+        $msg = $this->getRecord(Level::Error, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
 
         // format expected result
         $formatter = new ElasticaFormatter($this->options['index'], $this->options['type']);
@@ -158,7 +158,7 @@ class ElasticaHandlerTest extends TestCase
      */
     public function testHandleIntegration()
     {
-        $msg = $this->getRecord(Logger::ERROR, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
+        $msg = $this->getRecord(Level::Error, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
 
         $expected = $msg->toArray();
         $expected['datetime'] = $msg['datetime']->format(\DateTime::ISO8601);
@@ -204,7 +204,7 @@ class ElasticaHandlerTest extends TestCase
      */
     public function testHandleIntegrationNewESVersion()
     {
-        $msg = $this->getRecord(Logger::ERROR, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
+        $msg = $this->getRecord(Level::Error, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
 
         $expected = (array) $msg;
         $expected['datetime'] = $msg['datetime']->format(\DateTime::ISO8601);
diff --git a/tests/Monolog/Handler/ElasticsearchHandlerTest.php b/tests/Monolog/Handler/ElasticsearchHandlerTest.php
index ba4de76b..9009b71d 100644
--- a/tests/Monolog/Handler/ElasticsearchHandlerTest.php
+++ b/tests/Monolog/Handler/ElasticsearchHandlerTest.php
@@ -15,7 +15,7 @@ use Elasticsearch\ClientBuilder;
 use Monolog\Formatter\ElasticsearchFormatter;
 use Monolog\Formatter\NormalizerFormatter;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Elasticsearch\Client;
 
 class ElasticsearchHandlerTest extends TestCase
@@ -56,7 +56,7 @@ class ElasticsearchHandlerTest extends TestCase
     public function testHandle()
     {
         // log message
-        $msg = $this->getRecord(Logger::ERROR, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
+        $msg = $this->getRecord(Level::Error, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
 
         // format expected result
         $formatter = new ElasticsearchFormatter($this->options['index'], $this->options['type']);
@@ -172,7 +172,7 @@ class ElasticsearchHandlerTest extends TestCase
      */
     public function testHandleIntegration()
     {
-        $msg = $this->getRecord(Logger::ERROR, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
+        $msg = $this->getRecord(Level::Error, 'log', context: ['foo' => 7, 'bar', 'class' => new \stdClass], datetime: new \DateTimeImmutable("@0"));
 
         $expected = $msg->toArray();
         $expected['datetime'] = $msg['datetime']->format(\DateTime::ISO8601);
diff --git a/tests/Monolog/Handler/ErrorLogHandlerTest.php b/tests/Monolog/Handler/ErrorLogHandlerTest.php
index 10e8ec20..37bf58c5 100644
--- a/tests/Monolog/Handler/ErrorLogHandlerTest.php
+++ b/tests/Monolog/Handler/ErrorLogHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\LineFormatter;
 
 function error_log()
@@ -46,14 +46,14 @@ class ErrorLogHandlerTest extends TestCase
         $type = ErrorLogHandler::OPERATING_SYSTEM;
         $handler = new ErrorLogHandler($type);
         $handler->setFormatter(new LineFormatter('%channel%.%level_name%: %message% %context% %extra%', null, true));
-        $handler->handle($this->getRecord(Logger::ERROR, "Foo\nBar\r\n\r\nBaz"));
+        $handler->handle($this->getRecord(Level::Error, "Foo\nBar\r\n\r\nBaz"));
 
         $this->assertSame("test.ERROR: Foo\nBar\r\n\r\nBaz [] []", $GLOBALS['error_log'][0][0]);
         $this->assertSame($GLOBALS['error_log'][0][1], $type);
 
-        $handler = new ErrorLogHandler($type, Logger::DEBUG, true, true);
+        $handler = new ErrorLogHandler($type, Level::Debug, true, true);
         $handler->setFormatter(new LineFormatter(null, null, true));
-        $handler->handle($this->getRecord(Logger::ERROR, "Foo\nBar\r\n\r\nBaz"));
+        $handler->handle($this->getRecord(Level::Error, "Foo\nBar\r\n\r\nBaz"));
 
         $this->assertStringMatchesFormat('[%s] test.ERROR: Foo', $GLOBALS['error_log'][1][0]);
         $this->assertSame($GLOBALS['error_log'][1][1], $type);
diff --git a/tests/Monolog/Handler/FallbackGroupHandlerTest.php b/tests/Monolog/Handler/FallbackGroupHandlerTest.php
index 0cb149bc..b364c0ff 100644
--- a/tests/Monolog/Handler/FallbackGroupHandlerTest.php
+++ b/tests/Monolog/Handler/FallbackGroupHandlerTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class FallbackGroupHandlerTest extends TestCase
@@ -26,8 +26,8 @@ class FallbackGroupHandlerTest extends TestCase
         $testHandlerTwo = new TestHandler();
         $testHandlers = [$testHandlerOne, $testHandlerTwo];
         $handler = new FallbackGroupHandler($testHandlers);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
 
         $this->assertCount(2, $testHandlerOne->getRecords());
         $this->assertCount(0, $testHandlerTwo->getRecords());
@@ -43,8 +43,8 @@ class FallbackGroupHandlerTest extends TestCase
         $testHandlerTwo = new TestHandler();
         $testHandlers = [$testHandlerOne, $testHandlerTwo];
         $handler = new FallbackGroupHandler($testHandlers);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
 
         $this->assertCount(0, $testHandlerOne->getRecords());
         $this->assertCount(2, $testHandlerTwo->getRecords());
@@ -59,7 +59,7 @@ class FallbackGroupHandlerTest extends TestCase
         $testHandlerTwo = new TestHandler();
         $testHandlers = [$testHandlerOne, $testHandlerTwo];
         $handler = new FallbackGroupHandler($testHandlers);
-        $handler->handleBatch([$this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO)]);
+        $handler->handleBatch([$this->getRecord(Level::Debug), $this->getRecord(Level::Info)]);
         $this->assertCount(2, $testHandlerOne->getRecords());
         $this->assertCount(0, $testHandlerTwo->getRecords());
     }
@@ -73,7 +73,7 @@ class FallbackGroupHandlerTest extends TestCase
         $testHandlerTwo = new TestHandler();
         $testHandlers = [$testHandlerOne, $testHandlerTwo];
         $handler = new FallbackGroupHandler($testHandlers);
-        $handler->handleBatch([$this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO)]);
+        $handler->handleBatch([$this->getRecord(Level::Debug), $this->getRecord(Level::Info)]);
         $this->assertCount(0, $testHandlerOne->getRecords());
         $this->assertCount(2, $testHandlerTwo->getRecords());
     }
@@ -83,11 +83,11 @@ class FallbackGroupHandlerTest extends TestCase
      */
     public function testIsHandling()
     {
-        $testHandlers = [new TestHandler(Logger::ERROR), new TestHandler(Logger::WARNING)];
+        $testHandlers = [new TestHandler(Level::Error), new TestHandler(Level::Warning)];
         $handler = new FallbackGroupHandler($testHandlers);
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::ERROR)));
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::WARNING)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::DEBUG)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Error)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Warning)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Debug)));
     }
 
     /**
@@ -102,7 +102,7 @@ class FallbackGroupHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasWarningRecords());
         $records = $test->getRecords();
         $this->assertTrue($records[0]['extra']['foo']);
@@ -127,7 +127,7 @@ class FallbackGroupHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handleBatch([$this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO)]);
+        $handler->handleBatch([$this->getRecord(Level::Debug), $this->getRecord(Level::Info)]);
         $this->assertEmpty($testHandlerOne->getRecords());
         $this->assertTrue($testHandlerTwo->hasDebugRecords());
         $this->assertTrue($testHandlerTwo->hasInfoRecords());
diff --git a/tests/Monolog/Handler/FilterHandlerTest.php b/tests/Monolog/Handler/FilterHandlerTest.php
index 49ecb12b..4fa2eb79 100644
--- a/tests/Monolog/Handler/FilterHandlerTest.php
+++ b/tests/Monolog/Handler/FilterHandlerTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class FilterHandlerTest extends TestCase
@@ -22,15 +22,15 @@ class FilterHandlerTest extends TestCase
     public function testIsHandling()
     {
         $test    = new TestHandler();
-        $handler = new FilterHandler($test, Logger::INFO, Logger::NOTICE);
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::DEBUG)));
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::INFO)));
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::NOTICE)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::WARNING)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::ERROR)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::CRITICAL)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::ALERT)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::EMERGENCY)));
+        $handler = new FilterHandler($test, Level::Info, Level::Notice);
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Debug)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Info)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Notice)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Warning)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Error)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Critical)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Alert)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Emergency)));
     }
 
     /**
@@ -41,39 +41,39 @@ class FilterHandlerTest extends TestCase
     public function testHandleProcessOnlyNeededLevels()
     {
         $test    = new TestHandler();
-        $handler = new FilterHandler($test, Logger::INFO, Logger::NOTICE);
+        $handler = new FilterHandler($test, Level::Info, Level::Notice);
 
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Debug));
         $this->assertFalse($test->hasDebugRecords());
 
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertTrue($test->hasInfoRecords());
-        $handler->handle($this->getRecord(Logger::NOTICE));
+        $handler->handle($this->getRecord(Level::Notice));
         $this->assertTrue($test->hasNoticeRecords());
 
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertFalse($test->hasWarningRecords());
-        $handler->handle($this->getRecord(Logger::ERROR));
+        $handler->handle($this->getRecord(Level::Error));
         $this->assertFalse($test->hasErrorRecords());
-        $handler->handle($this->getRecord(Logger::CRITICAL));
+        $handler->handle($this->getRecord(Level::Critical));
         $this->assertFalse($test->hasCriticalRecords());
-        $handler->handle($this->getRecord(Logger::ALERT));
+        $handler->handle($this->getRecord(Level::Alert));
         $this->assertFalse($test->hasAlertRecords());
-        $handler->handle($this->getRecord(Logger::EMERGENCY));
+        $handler->handle($this->getRecord(Level::Emergency));
         $this->assertFalse($test->hasEmergencyRecords());
 
         $test    = new TestHandler();
-        $handler = new FilterHandler($test, [Logger::INFO, Logger::ERROR]);
+        $handler = new FilterHandler($test, [Level::Info, Level::Error]);
 
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Debug));
         $this->assertFalse($test->hasDebugRecords());
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertTrue($test->hasInfoRecords());
-        $handler->handle($this->getRecord(Logger::NOTICE));
+        $handler->handle($this->getRecord(Level::Notice));
         $this->assertFalse($test->hasNoticeRecords());
-        $handler->handle($this->getRecord(Logger::ERROR));
+        $handler->handle($this->getRecord(Level::Error));
         $this->assertTrue($test->hasErrorRecords());
-        $handler->handle($this->getRecord(Logger::CRITICAL));
+        $handler->handle($this->getRecord(Level::Critical));
         $this->assertFalse($test->hasCriticalRecords());
     }
 
@@ -86,15 +86,16 @@ class FilterHandlerTest extends TestCase
         $test    = new TestHandler();
         $handler = new FilterHandler($test);
 
-        $levels = [Logger::INFO, Logger::ERROR];
+        $levels = [Level::Info, Level::Error];
+        $levelsExpect = [Level::Info, Level::Error];
         $handler->setAcceptedLevels($levels);
-        $this->assertSame($levels, $handler->getAcceptedLevels());
+        $this->assertSame($levelsExpect, $handler->getAcceptedLevels());
 
         $handler->setAcceptedLevels(['info', 'error']);
-        $this->assertSame($levels, $handler->getAcceptedLevels());
+        $this->assertSame($levelsExpect, $handler->getAcceptedLevels());
 
-        $levels = [Logger::CRITICAL, Logger::ALERT, Logger::EMERGENCY];
-        $handler->setAcceptedLevels(Logger::CRITICAL, Logger::EMERGENCY);
+        $levels = [Level::Critical, Level::Alert, Level::Emergency];
+        $handler->setAcceptedLevels(Level::Critical, Level::Emergency);
         $this->assertSame($levels, $handler->getAcceptedLevels());
 
         $handler->setAcceptedLevels('critical', 'emergency');
@@ -107,7 +108,7 @@ class FilterHandlerTest extends TestCase
     public function testHandleUsesProcessors()
     {
         $test    = new TestHandler();
-        $handler = new FilterHandler($test, Logger::DEBUG, Logger::EMERGENCY);
+        $handler = new FilterHandler($test, Level::Debug, Level::Emergency);
         $handler->pushProcessor(
             function ($record) {
                 $record->extra['foo'] = true;
@@ -115,7 +116,7 @@ class FilterHandlerTest extends TestCase
                 return $record;
             }
         );
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasWarningRecords());
         $records = $test->getRecords();
         $this->assertTrue($records[0]['extra']['foo']);
@@ -128,13 +129,13 @@ class FilterHandlerTest extends TestCase
     {
         $test = new TestHandler();
 
-        $handler = new FilterHandler($test, Logger::INFO, Logger::NOTICE, false);
-        $this->assertTrue($handler->handle($this->getRecord(Logger::INFO)));
-        $this->assertFalse($handler->handle($this->getRecord(Logger::WARNING)));
+        $handler = new FilterHandler($test, Level::Info, Level::Notice, false);
+        $this->assertTrue($handler->handle($this->getRecord(Level::Info)));
+        $this->assertFalse($handler->handle($this->getRecord(Level::Warning)));
 
-        $handler = new FilterHandler($test, Logger::INFO, Logger::NOTICE, true);
-        $this->assertFalse($handler->handle($this->getRecord(Logger::INFO)));
-        $this->assertFalse($handler->handle($this->getRecord(Logger::WARNING)));
+        $handler = new FilterHandler($test, Level::Info, Level::Notice, true);
+        $this->assertFalse($handler->handle($this->getRecord(Level::Info)));
+        $this->assertFalse($handler->handle($this->getRecord(Level::Warning)));
     }
 
     /**
@@ -147,12 +148,12 @@ class FilterHandlerTest extends TestCase
             function ($record, $handler) use ($test) {
                 return $test;
             },
-            Logger::INFO,
-            Logger::NOTICE,
+            Level::Info,
+            Level::Notice,
             false
         );
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertFalse($test->hasDebugRecords());
         $this->assertTrue($test->hasInfoRecords());
     }
@@ -170,7 +171,7 @@ class FilterHandlerTest extends TestCase
 
         $this->expectException(\RuntimeException::class);
 
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
     }
 
     public function testHandleEmptyBatch()
@@ -188,12 +189,12 @@ class FilterHandlerTest extends TestCase
     public function testResetTestHandler()
     {
         $test = new TestHandler();
-        $handler = new FilterHandler($test, [Logger::INFO, Logger::ERROR]);
+        $handler = new FilterHandler($test, [Level::Info, Level::Error]);
 
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertTrue($test->hasInfoRecords());
 
-        $handler->handle($this->getRecord(Logger::ERROR));
+        $handler->handle($this->getRecord(Level::Error));
         $this->assertTrue($test->hasErrorRecords());
 
         $handler->reset();
diff --git a/tests/Monolog/Handler/FingersCrossedHandlerTest.php b/tests/Monolog/Handler/FingersCrossedHandlerTest.php
index 8847a16d..702a5f08 100644
--- a/tests/Monolog/Handler/FingersCrossedHandlerTest.php
+++ b/tests/Monolog/Handler/FingersCrossedHandlerTest.php
@@ -11,8 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
 use Monolog\Handler\FingersCrossed\ErrorLevelActivationStrategy;
 use Monolog\Handler\FingersCrossed\ChannelLevelActivationStrategy;
 use Psr\Log\LogLevel;
@@ -28,11 +28,11 @@ class FingersCrossedHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new FingersCrossedHandler($test);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertFalse($test->hasDebugRecords());
         $this->assertFalse($test->hasInfoRecords());
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $handler->close();
         $this->assertTrue($test->hasInfoRecords());
         $this->assertCount(3, $test->getRecords());
@@ -46,8 +46,8 @@ class FingersCrossedHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new FingersCrossedHandler($test);
-        $handler->handle($this->getRecord(Logger::WARNING));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Warning));
+        $handler->handle($this->getRecord(Level::Debug));
         $handler->close();
         $this->assertTrue($test->hasWarningRecords());
         $this->assertTrue($test->hasDebugRecords());
@@ -63,10 +63,10 @@ class FingersCrossedHandlerTest extends TestCase
         $test = new TestHandler();
         $test->setSkipReset(true);
         $handler = new FingersCrossedHandler($test);
-        $handler->handle($this->getRecord(Logger::WARNING));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Warning));
+        $handler->handle($this->getRecord(Level::Debug));
         $handler->reset();
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Info));
         $handler->close();
         $this->assertTrue($test->hasWarningRecords());
         $this->assertTrue($test->hasDebugRecords());
@@ -80,10 +80,10 @@ class FingersCrossedHandlerTest extends TestCase
     public function testHandleResetBufferingAfterBeingTriggeredWhenStopBufferingIsDisabled()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, Logger::WARNING, 0, false, false);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::WARNING));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler = new FingersCrossedHandler($test, Level::Warning, 0, false, false);
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Warning));
+        $handler->handle($this->getRecord(Level::Info));
         $handler->close();
         $this->assertTrue($test->hasWarningRecords());
         $this->assertTrue($test->hasDebugRecords());
@@ -97,11 +97,11 @@ class FingersCrossedHandlerTest extends TestCase
     public function testHandleBufferLimit()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, Logger::WARNING, 2);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler = new FingersCrossedHandler($test, Level::Warning, 2);
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasWarningRecords());
         $this->assertTrue($test->hasInfoRecords());
         $this->assertFalse($test->hasDebugRecords());
@@ -117,11 +117,11 @@ class FingersCrossedHandlerTest extends TestCase
         $handler = new FingersCrossedHandler(function ($record, $handler) use ($test) {
             return $test;
         });
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertFalse($test->hasDebugRecords());
         $this->assertFalse($test->hasInfoRecords());
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasInfoRecords());
         $this->assertCount(3, $test->getRecords());
     }
@@ -138,7 +138,7 @@ class FingersCrossedHandlerTest extends TestCase
 
         $this->expectException(\RuntimeException::class);
 
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
     }
 
     /**
@@ -147,8 +147,8 @@ class FingersCrossedHandlerTest extends TestCase
     public function testIsHandlingAlways()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, Logger::ERROR);
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::DEBUG)));
+        $handler = new FingersCrossedHandler($test, Level::Error);
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Debug)));
     }
 
     /**
@@ -159,10 +159,10 @@ class FingersCrossedHandlerTest extends TestCase
     public function testErrorLevelActivationStrategy()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy(Logger::WARNING));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy(Level::Warning));
+        $handler->handle($this->getRecord(Level::Debug));
         $this->assertFalse($test->hasDebugRecords());
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasDebugRecords());
         $this->assertTrue($test->hasWarningRecords());
     }
@@ -176,9 +176,9 @@ class FingersCrossedHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy('warning'));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Debug));
         $this->assertFalse($test->hasDebugRecords());
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasDebugRecords());
         $this->assertTrue($test->hasWarningRecords());
     }
@@ -191,11 +191,11 @@ class FingersCrossedHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy('warning'));
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Debug));
         $this->assertFalse($test->hasDebugRecords());
         $handler->activate();
         $this->assertTrue($test->hasDebugRecords());
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Info));
         $this->assertTrue($test->hasInfoRecords());
     }
 
@@ -206,10 +206,10 @@ class FingersCrossedHandlerTest extends TestCase
     public function testChannelLevelActivationStrategy()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, new ChannelLevelActivationStrategy(Logger::ERROR, ['othertest' => Logger::DEBUG]));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler = new FingersCrossedHandler($test, new ChannelLevelActivationStrategy(Level::Error, ['othertest' => Level::Debug]));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertFalse($test->hasWarningRecords());
-        $record = $this->getRecord(Logger::DEBUG, channel: 'othertest');
+        $record = $this->getRecord(Level::Debug, channel: 'othertest');
         $handler->handle($record);
         $this->assertTrue($test->hasDebugRecords());
         $this->assertTrue($test->hasWarningRecords());
@@ -223,9 +223,9 @@ class FingersCrossedHandlerTest extends TestCase
     {
         $test = new TestHandler();
         $handler = new FingersCrossedHandler($test, new ChannelLevelActivationStrategy('error', ['othertest' => 'debug']));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertFalse($test->hasWarningRecords());
-        $record = $this->getRecord(Logger::DEBUG, channel: 'othertest');
+        $record = $this->getRecord(Level::Debug, channel: 'othertest');
         $handler->handle($record);
         $this->assertTrue($test->hasDebugRecords());
         $this->assertTrue($test->hasWarningRecords());
@@ -238,13 +238,13 @@ class FingersCrossedHandlerTest extends TestCase
     public function testHandleUsesProcessors()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, Logger::INFO);
+        $handler = new FingersCrossedHandler($test, Level::Info);
         $handler->pushProcessor(function ($record) {
             $record->extra['foo'] = true;
 
             return $record;
         });
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasWarningRecords());
         $records = $test->getRecords();
         $this->assertTrue($records[0]['extra']['foo']);
@@ -256,9 +256,9 @@ class FingersCrossedHandlerTest extends TestCase
     public function testPassthruOnClose()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy(Logger::WARNING), 0, true, true, Logger::INFO);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy(Level::Warning), 0, true, true, Level::Info);
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         $handler->close();
         $this->assertFalse($test->hasDebugRecords());
         $this->assertTrue($test->hasInfoRecords());
@@ -270,9 +270,9 @@ class FingersCrossedHandlerTest extends TestCase
     public function testPsrLevelPassthruOnClose()
     {
         $test = new TestHandler();
-        $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy(Logger::WARNING), 0, true, true, LogLevel::INFO);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler = new FingersCrossedHandler($test, new ErrorLevelActivationStrategy(Level::Warning), 0, true, true, LogLevel::INFO);
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         $handler->close();
         $this->assertFalse($test->hasDebugRecords());
         $this->assertTrue($test->hasInfoRecords());
diff --git a/tests/Monolog/Handler/FirePHPHandlerTest.php b/tests/Monolog/Handler/FirePHPHandlerTest.php
index cd8fa1be..fd28b95a 100644
--- a/tests/Monolog/Handler/FirePHPHandlerTest.php
+++ b/tests/Monolog/Handler/FirePHPHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @covers Monolog\Handler\FirePHPHandler
@@ -29,8 +29,8 @@ class FirePHPHandlerTest extends TestCase
     {
         $handler = new TestFirePHPHandler;
         $handler->setFormatter($this->getIdentityFormatter());
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Warning));
 
         $expected = [
             'X-Wf-Protocol-1'    => 'http://meta.wildfirehq.org/Protocol/JsonStream/0.2',
@@ -47,13 +47,13 @@ class FirePHPHandlerTest extends TestCase
     {
         $handler = new TestFirePHPHandler;
         $handler->setFormatter($this->getIdentityFormatter());
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Warning));
 
         $handler2 = new TestFirePHPHandler;
         $handler2->setFormatter($this->getIdentityFormatter());
-        $handler2->handle($this->getRecord(Logger::DEBUG));
-        $handler2->handle($this->getRecord(Logger::WARNING));
+        $handler2->handle($this->getRecord(Level::Debug));
+        $handler2->handle($this->getRecord(Level::Warning));
 
         $expected = [
             'X-Wf-Protocol-1'    => 'http://meta.wildfirehq.org/Protocol/JsonStream/0.2',
diff --git a/tests/Monolog/Handler/FleepHookHandlerTest.php b/tests/Monolog/Handler/FleepHookHandlerTest.php
index 029d0508..4f865526 100644
--- a/tests/Monolog/Handler/FleepHookHandlerTest.php
+++ b/tests/Monolog/Handler/FleepHookHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Formatter\LineFormatter;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 /**
@@ -47,7 +47,7 @@ class FleepHookHandlerTest extends TestCase
      */
     public function testConstructorSetsExpectedDefaults()
     {
-        $this->assertEquals(Logger::DEBUG, $this->handler->getLevel());
+        $this->assertEquals(Level::Debug, $this->handler->getLevel());
         $this->assertEquals(true, $this->handler->getBubble());
     }
 
@@ -56,7 +56,7 @@ class FleepHookHandlerTest extends TestCase
      */
     public function testHandlerUsesLineFormatterWhichIgnoresEmptyArrays()
     {
-        $record = $this->getRecord(Logger::DEBUG, 'msg');
+        $record = $this->getRecord(Level::Debug, 'msg');
 
         $expectedFormatter = new LineFormatter(null, null, true, true);
         $expected = $expectedFormatter->format($record);
diff --git a/tests/Monolog/Handler/FlowdockHandlerTest.php b/tests/Monolog/Handler/FlowdockHandlerTest.php
index c7612e33..10243098 100644
--- a/tests/Monolog/Handler/FlowdockHandlerTest.php
+++ b/tests/Monolog/Handler/FlowdockHandlerTest.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\FlowdockFormatter;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @author Dominik Liebler <liebler.dominik@gmail.com>
@@ -41,7 +41,7 @@ class FlowdockHandlerTest extends TestCase
     public function testWriteHeader()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -61,7 +61,7 @@ class FlowdockHandlerTest extends TestCase
 
     private function createHandler($token = 'myToken')
     {
-        $constructorArgs = [$token, Logger::DEBUG];
+        $constructorArgs = [$token, Level::Debug];
         $this->res = fopen('php://memory', 'a');
         $this->handler = $this->getMockBuilder('Monolog\Handler\FlowdockHandler')
             ->setConstructorArgs($constructorArgs)
diff --git a/tests/Monolog/Handler/GelfHandlerTest.php b/tests/Monolog/Handler/GelfHandlerTest.php
index 93117140..918f5324 100644
--- a/tests/Monolog/Handler/GelfHandlerTest.php
+++ b/tests/Monolog/Handler/GelfHandlerTest.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Gelf\Message;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\GelfMessageFormatter;
 
 class GelfHandlerTest extends TestCase
@@ -51,7 +51,7 @@ class GelfHandlerTest extends TestCase
 
     public function testDebug()
     {
-        $record = $this->getRecord(Logger::DEBUG, "A test debug message");
+        $record = $this->getRecord(Level::Debug, "A test debug message");
         $expectedMessage = new Message();
         $expectedMessage
             ->setLevel(7)
@@ -72,7 +72,7 @@ class GelfHandlerTest extends TestCase
 
     public function testWarning()
     {
-        $record = $this->getRecord(Logger::WARNING, "A test warning message");
+        $record = $this->getRecord(Level::Warning, "A test warning message");
         $expectedMessage = new Message();
         $expectedMessage
             ->setLevel(4)
@@ -94,7 +94,7 @@ class GelfHandlerTest extends TestCase
     public function testInjectedGelfMessageFormatter()
     {
         $record = $this->getRecord(
-            Logger::WARNING,
+            Level::Warning,
             "A test warning message",
             extra: ['blarg' => 'yep'],
             context: ['from' => 'logger'],
diff --git a/tests/Monolog/Handler/GroupHandlerTest.php b/tests/Monolog/Handler/GroupHandlerTest.php
index 97680db3..0c734dee 100644
--- a/tests/Monolog/Handler/GroupHandlerTest.php
+++ b/tests/Monolog/Handler/GroupHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class GroupHandlerTest extends TestCase
 {
@@ -34,8 +34,8 @@ class GroupHandlerTest extends TestCase
     {
         $testHandlers = [new TestHandler(), new TestHandler()];
         $handler = new GroupHandler($testHandlers);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         foreach ($testHandlers as $test) {
             $this->assertTrue($test->hasDebugRecords());
             $this->assertTrue($test->hasInfoRecords());
@@ -50,7 +50,7 @@ class GroupHandlerTest extends TestCase
     {
         $testHandlers = [new TestHandler(), new TestHandler()];
         $handler = new GroupHandler($testHandlers);
-        $handler->handleBatch([$this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO)]);
+        $handler->handleBatch([$this->getRecord(Level::Debug), $this->getRecord(Level::Info)]);
         foreach ($testHandlers as $test) {
             $this->assertTrue($test->hasDebugRecords());
             $this->assertTrue($test->hasInfoRecords());
@@ -63,11 +63,11 @@ class GroupHandlerTest extends TestCase
      */
     public function testIsHandling()
     {
-        $testHandlers = [new TestHandler(Logger::ERROR), new TestHandler(Logger::WARNING)];
+        $testHandlers = [new TestHandler(Level::Error), new TestHandler(Level::Warning)];
         $handler = new GroupHandler($testHandlers);
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::ERROR)));
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::WARNING)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::DEBUG)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Error)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Warning)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Debug)));
     }
 
     /**
@@ -82,7 +82,7 @@ class GroupHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasWarningRecords());
         $records = $test->getRecords();
         $this->assertTrue($records[0]['extra']['foo']);
@@ -105,7 +105,7 @@ class GroupHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handleBatch([$this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO)]);
+        $handler->handleBatch([$this->getRecord(Level::Debug), $this->getRecord(Level::Info)]);
         foreach ($testHandlers as $test) {
             $this->assertTrue($test->hasDebugRecords());
             $this->assertTrue($test->hasInfoRecords());
diff --git a/tests/Monolog/Handler/InsightOpsHandlerTest.php b/tests/Monolog/Handler/InsightOpsHandlerTest.php
index bbb1ff47..8663d777 100644
--- a/tests/Monolog/Handler/InsightOpsHandlerTest.php
+++ b/tests/Monolog/Handler/InsightOpsHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @author Robert Kaufmann III <rok3@rok3.me>
@@ -33,7 +33,7 @@ class InsightOpsHandlerTest extends TestCase
     public function testWriteContent()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'Critical write test'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'Critical write test'));
 
         fseek($this->resource, 0);
         $content = fread($this->resource, 1024);
@@ -55,7 +55,7 @@ class InsightOpsHandlerTest extends TestCase
     private function createHandler()
     {
         $useSSL = extension_loaded('openssl');
-        $args = array('testToken', 'us', $useSSL, Logger::DEBUG, true);
+        $args = array('testToken', 'us', $useSSL, Level::Debug, true);
         $this->resource = fopen('php://memory', 'a');
         $this->handler = $this->getMockBuilder(InsightOpsHandler::class)
             ->onlyMethods(array('fsockopen', 'streamSetTimeout', 'closeSocket'))
diff --git a/tests/Monolog/Handler/LogEntriesHandlerTest.php b/tests/Monolog/Handler/LogEntriesHandlerTest.php
index 1dcd6452..2f49fa91 100644
--- a/tests/Monolog/Handler/LogEntriesHandlerTest.php
+++ b/tests/Monolog/Handler/LogEntriesHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @author Robert Kaufmann III <rok3@rok3.me>
@@ -32,7 +32,7 @@ class LogEntriesHandlerTest extends TestCase
     public function testWriteContent()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'Critical write test'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'Critical write test'));
 
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
@@ -59,7 +59,7 @@ class LogEntriesHandlerTest extends TestCase
     private function createHandler()
     {
         $useSSL = extension_loaded('openssl');
-        $args = ['testToken', $useSSL, Logger::DEBUG, true];
+        $args = ['testToken', $useSSL, Level::Debug, true];
         $this->res = fopen('php://memory', 'a');
         $this->handler = $this->getMockBuilder('Monolog\Handler\LogEntriesHandler')
             ->setConstructorArgs($args)
diff --git a/tests/Monolog/Handler/LogmaticHandlerTest.php b/tests/Monolog/Handler/LogmaticHandlerTest.php
index d6c78134..953ca14b 100644
--- a/tests/Monolog/Handler/LogmaticHandlerTest.php
+++ b/tests/Monolog/Handler/LogmaticHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @author Julien Breux <julien.breux@gmail.com>
@@ -32,7 +32,7 @@ class LogmaticHandlerTest extends TestCase
     public function testWriteContent()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'Critical write test'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'Critical write test'));
 
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
@@ -59,7 +59,7 @@ class LogmaticHandlerTest extends TestCase
     private function createHandler()
     {
         $useSSL = extension_loaded('openssl');
-        $args = ['testToken', 'testHostname', 'testAppname', $useSSL, Logger::DEBUG, true];
+        $args = ['testToken', 'testHostname', 'testAppname', $useSSL, Level::Debug, true];
         $this->res = fopen('php://memory', 'a');
         $this->handler = $this->getMockBuilder('Monolog\Handler\LogmaticHandler')
             ->setConstructorArgs($args)
diff --git a/tests/Monolog/Handler/MailHandlerTest.php b/tests/Monolog/Handler/MailHandlerTest.php
index d85a7077..3c4a5805 100644
--- a/tests/Monolog/Handler/MailHandlerTest.php
+++ b/tests/Monolog/Handler/MailHandlerTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 class MailHandlerTest extends TestCase
@@ -42,15 +42,15 @@ class MailHandlerTest extends TestCase
     public function testHandleBatchNotSendsMailIfMessagesAreBelowLevel()
     {
         $records = [
-            $this->getRecord(Logger::DEBUG, 'debug message 1'),
-            $this->getRecord(Logger::DEBUG, 'debug message 2'),
-            $this->getRecord(Logger::INFO, 'information'),
+            $this->getRecord(Level::Debug, 'debug message 1'),
+            $this->getRecord(Level::Debug, 'debug message 2'),
+            $this->getRecord(Level::Info, 'information'),
         ];
 
         $handler = $this->getMockForAbstractClass('Monolog\\Handler\\MailHandler');
         $handler->expects($this->never())
             ->method('send');
-        $handler->setLevel(Logger::ERROR);
+        $handler->setLevel(Level::Error);
 
         $handler->handleBatch($records);
     }
diff --git a/tests/Monolog/Handler/NativeMailerHandlerTest.php b/tests/Monolog/Handler/NativeMailerHandlerTest.php
index 62f79b20..25564e9f 100644
--- a/tests/Monolog/Handler/NativeMailerHandlerTest.php
+++ b/tests/Monolog/Handler/NativeMailerHandlerTest.php
@@ -11,8 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
 
 function mail($to, $subject, $message, $additional_headers = null, $additional_parameters = null)
 {
@@ -79,7 +79,7 @@ class NativeMailerHandlerTest extends TestCase
         $this->assertEmpty($GLOBALS['mail']);
 
         // non-empty batch
-        $mailer->handle($this->getRecord(Logger::ERROR, "Foo\nBar\r\n\r\nBaz"));
+        $mailer->handle($this->getRecord(Level::Error, "Foo\nBar\r\n\r\nBaz"));
         $this->assertNotEmpty($GLOBALS['mail']);
         $this->assertIsArray($GLOBALS['mail']);
         $this->assertArrayHasKey('0', $GLOBALS['mail']);
@@ -95,7 +95,7 @@ class NativeMailerHandlerTest extends TestCase
     public function testMessageSubjectFormatting()
     {
         $mailer = new NativeMailerHandler('to@example.org', 'Alert: %level_name% %message%', 'from@example.org');
-        $mailer->handle($this->getRecord(Logger::ERROR, "Foo\nBar\r\n\r\nBaz"));
+        $mailer->handle($this->getRecord(Level::Error, "Foo\nBar\r\n\r\nBaz"));
         $this->assertNotEmpty($GLOBALS['mail']);
         $this->assertIsArray($GLOBALS['mail']);
         $this->assertArrayHasKey('0', $GLOBALS['mail']);
diff --git a/tests/Monolog/Handler/NewRelicHandlerTest.php b/tests/Monolog/Handler/NewRelicHandlerTest.php
index b60f0b78..17d7e833 100644
--- a/tests/Monolog/Handler/NewRelicHandlerTest.php
+++ b/tests/Monolog/Handler/NewRelicHandlerTest.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Formatter\LineFormatter;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class NewRelicHandlerTest extends TestCase
 {
@@ -34,27 +34,27 @@ class NewRelicHandlerTest extends TestCase
 
         $this->expectException(MissingExtensionException::class);
 
-        $handler->handle($this->getRecord(Logger::ERROR));
+        $handler->handle($this->getRecord(Level::Error));
     }
 
     public function testThehandlerCanHandleTheRecord()
     {
         $handler = new StubNewRelicHandler();
-        $handler->handle($this->getRecord(Logger::ERROR));
+        $handler->handle($this->getRecord(Level::Error));
     }
 
     public function testThehandlerCanAddContextParamsToTheNewRelicTrace()
     {
         $handler = new StubNewRelicHandler();
-        $handler->handle($this->getRecord(Logger::ERROR, 'log message', ['a' => 'b']));
+        $handler->handle($this->getRecord(Level::Error, 'log message', ['a' => 'b']));
         $this->assertEquals(['context_a' => 'b'], self::$customParameters);
     }
 
     public function testThehandlerCanAddExplodedContextParamsToTheNewRelicTrace()
     {
-        $handler = new StubNewRelicHandler(Logger::ERROR, true, self::$appname, true);
+        $handler = new StubNewRelicHandler(Level::Error, true, self::$appname, true);
         $handler->handle($this->getRecord(
-            Logger::ERROR,
+            Level::Error,
             'log message',
             ['a' => ['key1' => 'value1', 'key2' => 'value2']]
         ));
@@ -66,7 +66,7 @@ class NewRelicHandlerTest extends TestCase
 
     public function testThehandlerCanAddExtraParamsToTheNewRelicTrace()
     {
-        $record = $this->getRecord(Logger::ERROR, 'log message');
+        $record = $this->getRecord(Level::Error, 'log message');
         $record->extra = ['c' => 'd'];
 
         $handler = new StubNewRelicHandler();
@@ -77,10 +77,10 @@ class NewRelicHandlerTest extends TestCase
 
     public function testThehandlerCanAddExplodedExtraParamsToTheNewRelicTrace()
     {
-        $record = $this->getRecord(Logger::ERROR, 'log message');
+        $record = $this->getRecord(Level::Error, 'log message');
         $record->extra = ['c' => ['key1' => 'value1', 'key2' => 'value2']];
 
-        $handler = new StubNewRelicHandler(Logger::ERROR, true, self::$appname, true);
+        $handler = new StubNewRelicHandler(Level::Error, true, self::$appname, true);
         $handler->handle($record);
 
         $this->assertEquals(
@@ -91,7 +91,7 @@ class NewRelicHandlerTest extends TestCase
 
     public function testThehandlerCanAddExtraContextAndParamsToTheNewRelicTrace()
     {
-        $record = $this->getRecord(Logger::ERROR, 'log message', ['a' => 'b']);
+        $record = $this->getRecord(Level::Error, 'log message', ['a' => 'b']);
         $record->extra = ['c' => 'd'];
 
         $handler = new StubNewRelicHandler();
@@ -109,29 +109,29 @@ class NewRelicHandlerTest extends TestCase
     {
         $handler = new StubNewRelicHandler();
         $handler->setFormatter(new LineFormatter());
-        $handler->handle($this->getRecord(Logger::ERROR));
+        $handler->handle($this->getRecord(Level::Error));
     }
 
     public function testTheAppNameIsNullByDefault()
     {
         $handler = new StubNewRelicHandler();
-        $handler->handle($this->getRecord(Logger::ERROR, 'log message'));
+        $handler->handle($this->getRecord(Level::Error, 'log message'));
 
         $this->assertEquals(null, self::$appname);
     }
 
     public function testTheAppNameCanBeInjectedFromtheConstructor()
     {
-        $handler = new StubNewRelicHandler(Logger::DEBUG, false, 'myAppName');
-        $handler->handle($this->getRecord(Logger::ERROR, 'log message'));
+        $handler = new StubNewRelicHandler(Level::Debug, false, 'myAppName');
+        $handler->handle($this->getRecord(Level::Error, 'log message'));
 
         $this->assertEquals('myAppName', self::$appname);
     }
 
     public function testTheAppNameCanBeOverriddenFromEachLog()
     {
-        $handler = new StubNewRelicHandler(Logger::DEBUG, false, 'myAppName');
-        $handler->handle($this->getRecord(Logger::ERROR, 'log message', ['appname' => 'logAppName']));
+        $handler = new StubNewRelicHandler(Level::Debug, false, 'myAppName');
+        $handler->handle($this->getRecord(Level::Error, 'log message', ['appname' => 'logAppName']));
 
         $this->assertEquals('logAppName', self::$appname);
     }
@@ -139,23 +139,23 @@ class NewRelicHandlerTest extends TestCase
     public function testTheTransactionNameIsNullByDefault()
     {
         $handler = new StubNewRelicHandler();
-        $handler->handle($this->getRecord(Logger::ERROR, 'log message'));
+        $handler->handle($this->getRecord(Level::Error, 'log message'));
 
         $this->assertEquals(null, self::$transactionName);
     }
 
     public function testTheTransactionNameCanBeInjectedFromTheConstructor()
     {
-        $handler = new StubNewRelicHandler(Logger::DEBUG, false, null, false, 'myTransaction');
-        $handler->handle($this->getRecord(Logger::ERROR, 'log message'));
+        $handler = new StubNewRelicHandler(Level::Debug, false, null, false, 'myTransaction');
+        $handler->handle($this->getRecord(Level::Error, 'log message'));
 
         $this->assertEquals('myTransaction', self::$transactionName);
     }
 
     public function testTheTransactionNameCanBeOverriddenFromEachLog()
     {
-        $handler = new StubNewRelicHandler(Logger::DEBUG, false, null, false, 'myTransaction');
-        $handler->handle($this->getRecord(Logger::ERROR, 'log message', ['transaction_name' => 'logTransactName']));
+        $handler = new StubNewRelicHandler(Level::Debug, false, null, false, 'myTransaction');
+        $handler->handle($this->getRecord(Level::Error, 'log message', ['transaction_name' => 'logTransactName']));
 
         $this->assertEquals('logTransactName', self::$transactionName);
     }
diff --git a/tests/Monolog/Handler/NoopHandlerTest.php b/tests/Monolog/Handler/NoopHandlerTest.php
index 768f5e30..83cb6a2a 100644
--- a/tests/Monolog/Handler/NoopHandlerTest.php
+++ b/tests/Monolog/Handler/NoopHandlerTest.php
@@ -11,8 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
 
 /**
  * @covers Monolog\Handler\NoopHandler::handle
@@ -22,7 +22,7 @@ class NoopHandlerTest extends TestCase
     /**
      * @dataProvider logLevelsProvider
      */
-    public function testIsHandling($level)
+    public function testIsHandling(Level $level)
     {
         $handler = new NoopHandler();
         $this->assertTrue($handler->isHandling($this->getRecord($level)));
@@ -31,7 +31,7 @@ class NoopHandlerTest extends TestCase
     /**
      * @dataProvider logLevelsProvider
      */
-    public function testHandle($level)
+    public function testHandle(Level $level)
     {
         $handler = new NoopHandler();
         $this->assertFalse($handler->handle($this->getRecord($level)));
@@ -40,10 +40,8 @@ class NoopHandlerTest extends TestCase
     public function logLevelsProvider()
     {
         return array_map(
-            function ($level) {
-                return [$level];
-            },
-            array_values(Logger::getLevels())
+            fn ($level) => [$level],
+            Level::cases()
         );
     }
 }
diff --git a/tests/Monolog/Handler/NullHandlerTest.php b/tests/Monolog/Handler/NullHandlerTest.php
index b7e482ba..d6a80074 100644
--- a/tests/Monolog/Handler/NullHandlerTest.php
+++ b/tests/Monolog/Handler/NullHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * @covers Monolog\Handler\NullHandler::handle
@@ -27,7 +27,7 @@ class NullHandlerTest extends TestCase
 
     public function testHandleLowerLevelRecord()
     {
-        $handler = new NullHandler(Logger::WARNING);
-        $this->assertFalse($handler->handle($this->getRecord(Logger::DEBUG)));
+        $handler = new NullHandler(Level::Warning);
+        $this->assertFalse($handler->handle($this->getRecord(Level::Debug)));
     }
 }
diff --git a/tests/Monolog/Handler/OverflowHandlerTest.php b/tests/Monolog/Handler/OverflowHandlerTest.php
index c62f441a..e50966f9 100644
--- a/tests/Monolog/Handler/OverflowHandlerTest.php
+++ b/tests/Monolog/Handler/OverflowHandlerTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 /**
@@ -23,19 +23,19 @@ class OverflowHandlerTest extends TestCase
     public function testNotPassingRecordsBeneathLogLevel()
     {
         $testHandler = new TestHandler();
-        $handler = new OverflowHandler($testHandler, [], Logger::INFO);
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler = new OverflowHandler($testHandler, [], Level::Info);
+        $handler->handle($this->getRecord(Level::Debug));
         $this->assertFalse($testHandler->hasDebugRecords());
     }
 
     public function testPassThroughWithoutThreshold()
     {
         $testHandler = new TestHandler();
-        $handler = new OverflowHandler($testHandler, [], Logger::INFO);
+        $handler = new OverflowHandler($testHandler, [], Level::Info);
 
-        $handler->handle($this->getRecord(Logger::INFO, 'Info 1'));
-        $handler->handle($this->getRecord(Logger::INFO, 'Info 2'));
-        $handler->handle($this->getRecord(Logger::WARNING, 'Warning 1'));
+        $handler->handle($this->getRecord(Level::Info, 'Info 1'));
+        $handler->handle($this->getRecord(Level::Info, 'Info 2'));
+        $handler->handle($this->getRecord(Level::Warning, 'Warning 1'));
 
         $this->assertTrue($testHandler->hasInfoThatContains('Info 1'));
         $this->assertTrue($testHandler->hasInfoThatContains('Info 2'));
@@ -48,20 +48,20 @@ class OverflowHandlerTest extends TestCase
     public function testHoldingMessagesBeneathThreshold()
     {
         $testHandler = new TestHandler();
-        $handler = new OverflowHandler($testHandler, [Logger::INFO => 3]);
+        $handler = new OverflowHandler($testHandler, [Level::Info->value => 3]);
 
-        $handler->handle($this->getRecord(Logger::DEBUG, 'debug 1'));
-        $handler->handle($this->getRecord(Logger::DEBUG, 'debug 2'));
+        $handler->handle($this->getRecord(Level::Debug, 'debug 1'));
+        $handler->handle($this->getRecord(Level::Debug, 'debug 2'));
 
         foreach (range(1, 3) as $i) {
-            $handler->handle($this->getRecord(Logger::INFO, 'info ' . $i));
+            $handler->handle($this->getRecord(Level::Info, 'info ' . $i));
         }
 
         $this->assertTrue($testHandler->hasDebugThatContains('debug 1'));
         $this->assertTrue($testHandler->hasDebugThatContains('debug 2'));
         $this->assertFalse($testHandler->hasInfoRecords());
 
-        $handler->handle($this->getRecord(Logger::INFO, 'info 4'));
+        $handler->handle($this->getRecord(Level::Info, 'info 4'));
 
         foreach (range(1, 4) as $i) {
             $this->assertTrue($testHandler->hasInfoThatContains('info ' . $i));
@@ -74,33 +74,33 @@ class OverflowHandlerTest extends TestCase
     public function testCombinedThresholds()
     {
         $testHandler = new TestHandler();
-        $handler = new OverflowHandler($testHandler, [Logger::INFO => 5, Logger::WARNING => 10]);
+        $handler = new OverflowHandler($testHandler, [Level::Info->value => 5, Level::Warning->value => 10]);
 
-        $handler->handle($this->getRecord(Logger::DEBUG));
+        $handler->handle($this->getRecord(Level::Debug));
 
         foreach (range(1, 5) as $i) {
-            $handler->handle($this->getRecord(Logger::INFO, 'info ' . $i));
+            $handler->handle($this->getRecord(Level::Info, 'info ' . $i));
         }
 
         foreach (range(1, 10) as $i) {
-            $handler->handle($this->getRecord(Logger::WARNING, 'warning ' . $i));
+            $handler->handle($this->getRecord(Level::Warning, 'warning ' . $i));
         }
 
         // Only 1 DEBUG records
         $this->assertCount(1, $testHandler->getRecords());
 
-        $handler->handle($this->getRecord(Logger::INFO, 'info final'));
+        $handler->handle($this->getRecord(Level::Info, 'info final'));
 
         // 1 DEBUG + 5 buffered INFO + 1 new INFO
         $this->assertCount(7, $testHandler->getRecords());
 
-        $handler->handle($this->getRecord(Logger::WARNING, 'warning final'));
+        $handler->handle($this->getRecord(Level::Warning, 'warning final'));
 
         // 1 DEBUG + 6 INFO + 10 buffered WARNING + 1 new WARNING
         $this->assertCount(18, $testHandler->getRecords());
 
-        $handler->handle($this->getRecord(Logger::INFO, 'Another info'));
-        $handler->handle($this->getRecord(Logger::WARNING, 'Anther warning'));
+        $handler->handle($this->getRecord(Level::Info, 'Another info'));
+        $handler->handle($this->getRecord(Level::Warning, 'Anther warning'));
 
         // 1 DEBUG + 6 INFO + 11 WARNING + 1 new INFO + 1 new WARNING
         $this->assertCount(20, $testHandler->getRecords());
diff --git a/tests/Monolog/Handler/PHPConsoleHandlerTest.php b/tests/Monolog/Handler/PHPConsoleHandlerTest.php
index 98d8a4b2..84dc911a 100644
--- a/tests/Monolog/Handler/PHPConsoleHandlerTest.php
+++ b/tests/Monolog/Handler/PHPConsoleHandlerTest.php
@@ -13,6 +13,7 @@ namespace Monolog\Handler;
 
 use Exception;
 use Monolog\ErrorHandler;
+use Monolog\Level;
 use Monolog\Logger;
 use Monolog\Test\TestCase;
 use PhpConsole\Connector;
@@ -107,7 +108,7 @@ class PHPConsoleHandlerTest extends TestCase
         return $options[$name];
     }
 
-    protected function initLogger($handlerOptions = [], $level = Logger::DEBUG)
+    protected function initLogger($handlerOptions = [], $level = Level::Debug)
     {
         return new Logger('test', [
             new PHPConsoleHandler($handlerOptions, $this->connector, $level),
diff --git a/tests/Monolog/Handler/ProcessHandlerTest.php b/tests/Monolog/Handler/ProcessHandlerTest.php
index 7a71c4d2..daa4ae55 100644
--- a/tests/Monolog/Handler/ProcessHandlerTest.php
+++ b/tests/Monolog/Handler/ProcessHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class ProcessHandlerTest extends TestCase
 {
@@ -51,8 +51,8 @@ class ProcessHandlerTest extends TestCase
             ->withConsecutive([$this->stringContains($fixtures[0])], [$this->stringContains($fixtures[1])]);
 
         /** @var ProcessHandler $handler */
-        $handler->handle($this->getRecord(Logger::WARNING, $fixtures[0]));
-        $handler->handle($this->getRecord(Logger::ERROR, $fixtures[1]));
+        $handler->handle($this->getRecord(Level::Warning, $fixtures[0]));
+        $handler->handle($this->getRecord(Level::Error, $fixtures[1]));
     }
 
     /**
@@ -78,7 +78,7 @@ class ProcessHandlerTest extends TestCase
     public function testConstructWithInvalidCommandThrowsInvalidArgumentException($invalidCommand, $expectedExcep)
     {
         $this->expectException($expectedExcep);
-        new ProcessHandler($invalidCommand, Logger::DEBUG);
+        new ProcessHandler($invalidCommand, Level::Debug);
     }
 
     /**
@@ -103,7 +103,7 @@ class ProcessHandlerTest extends TestCase
     public function testConstructWithInvalidCwdThrowsInvalidArgumentException($invalidCwd, $expectedExcep)
     {
         $this->expectException($expectedExcep);
-        new ProcessHandler(self::DUMMY_COMMAND, Logger::DEBUG, true, $invalidCwd);
+        new ProcessHandler(self::DUMMY_COMMAND, Level::Debug, true, $invalidCwd);
     }
 
     /**
@@ -112,7 +112,7 @@ class ProcessHandlerTest extends TestCase
      */
     public function testConstructWithValidCwdWorks()
     {
-        $handler = new ProcessHandler(self::DUMMY_COMMAND, Logger::DEBUG, true, sys_get_temp_dir());
+        $handler = new ProcessHandler(self::DUMMY_COMMAND, Level::Debug, true, sys_get_temp_dir());
         $this->assertInstanceOf(
             'Monolog\Handler\ProcessHandler',
             $handler,
@@ -137,7 +137,7 @@ class ProcessHandlerTest extends TestCase
 
         $this->expectException(\UnexpectedValueException::class);
         /** @var ProcessHandler $handler */
-        $handler->handle($this->getRecord(Logger::WARNING, 'stream failing, whoops'));
+        $handler->handle($this->getRecord(Level::Warning, 'stream failing, whoops'));
     }
 
     /**
@@ -150,7 +150,7 @@ class ProcessHandlerTest extends TestCase
 
         $this->expectException(\UnexpectedValueException::class);
 
-        $handler->handle($this->getRecord(Logger::WARNING, 'some warning in the house'));
+        $handler->handle($this->getRecord(Level::Warning, 'some warning in the house'));
     }
 
     /**
@@ -171,7 +171,7 @@ class ProcessHandlerTest extends TestCase
 
         $this->expectException(\UnexpectedValueException::class);
         /** @var ProcessHandler $handler */
-        $handler->handle($this->getRecord(Logger::WARNING, 'some test stuff'));
+        $handler->handle($this->getRecord(Level::Warning, 'some test stuff'));
     }
 
     /**
@@ -184,7 +184,7 @@ class ProcessHandlerTest extends TestCase
         $property->setAccessible(true);
 
         $handler = new ProcessHandler(self::DUMMY_COMMAND);
-        $handler->handle($this->getRecord(Logger::WARNING, '21 is only the half truth'));
+        $handler->handle($this->getRecord(Level::Warning, '21 is only the half truth'));
 
         $process = $property->getValue($handler);
         $this->assertTrue(is_resource($process), 'Process is not running although it should.');
diff --git a/tests/Monolog/Handler/PsrHandlerTest.php b/tests/Monolog/Handler/PsrHandlerTest.php
index e3f30bfa..e06aa20e 100644
--- a/tests/Monolog/Handler/PsrHandlerTest.php
+++ b/tests/Monolog/Handler/PsrHandlerTest.php
@@ -11,8 +11,9 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
 use Monolog\Formatter\LineFormatter;
 
 /**
@@ -22,28 +23,24 @@ class PsrHandlerTest extends TestCase
 {
     public function logLevelProvider()
     {
-        $levels = [];
-        $monologLogger = new Logger('');
-
-        foreach ($monologLogger->getLevels() as $levelName => $level) {
-            $levels[] = [$levelName, $level];
-        }
-
-        return $levels;
+        return array_map(
+            fn(Level $level) => [$level->toLevelName(), $level],
+            Level::cases()
+        );
     }
 
     /**
      * @dataProvider logLevelProvider
      */
-    public function testHandlesAllLevels($levelName, $level)
+    public function testHandlesAllLevels(LevelName $levelName, Level $level)
     {
-        $message = 'Hello, world! ' . $level;
-        $context = ['foo' => 'bar', 'level' => $level];
+        $message = 'Hello, world! ' . $level->value;
+        $context = ['foo' => 'bar', 'level' => $level->value];
 
         $psrLogger = $this->createMock('Psr\Log\NullLogger');
         $psrLogger->expects($this->once())
             ->method('log')
-            ->with(strtolower($levelName), $message, $context);
+            ->with(strtolower($levelName->value), $message, $context);
 
         $handler = new PsrHandler($psrLogger);
         $handler->handle($this->getRecord($level, $message, context: $context));
@@ -53,13 +50,13 @@ class PsrHandlerTest extends TestCase
     {
         $message = 'Hello, world!';
         $context = ['foo' => 'bar'];
-        $level = Logger::ERROR;
-        $levelName = 'error';
+        $level = Level::Error;
+        $levelName = LevelName::Error;
 
         $psrLogger = $this->createMock('Psr\Log\NullLogger');
         $psrLogger->expects($this->once())
             ->method('log')
-            ->with(strtolower($levelName), 'dummy', $context);
+            ->with(strtolower($levelName->value), 'dummy', $context);
 
         $handler = new PsrHandler($psrLogger);
         $handler->setFormatter(new LineFormatter('dummy'));
diff --git a/tests/Monolog/Handler/PushoverHandlerTest.php b/tests/Monolog/Handler/PushoverHandlerTest.php
index b41ead54..7db7098e 100644
--- a/tests/Monolog/Handler/PushoverHandlerTest.php
+++ b/tests/Monolog/Handler/PushoverHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 /**
  * Almost all examples (expected header, titles, messages) taken from
@@ -28,8 +28,8 @@ class PushoverHandlerTest extends TestCase
     public function testWriteHeader()
     {
         $this->createHandler();
-        $this->handler->setHighPriorityLevel(Logger::EMERGENCY); // skip priority notifications
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->setHighPriorityLevel(Level::Emergency); // skip priority notifications
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -49,7 +49,7 @@ class PushoverHandlerTest extends TestCase
     public function testWriteWithComplexTitle()
     {
         $this->createHandler('myToken', 'myUser', 'Backup finished - SQL1');
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -59,8 +59,8 @@ class PushoverHandlerTest extends TestCase
     public function testWriteWithComplexMessage()
     {
         $this->createHandler();
-        $this->handler->setHighPriorityLevel(Logger::EMERGENCY); // skip priority notifications
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'Backup of database "example" finished in 16 minutes.'));
+        $this->handler->setHighPriorityLevel(Level::Emergency); // skip priority notifications
+        $this->handler->handle($this->getRecord(Level::Critical, 'Backup of database "example" finished in 16 minutes.'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -71,8 +71,8 @@ class PushoverHandlerTest extends TestCase
     {
         $message = str_pad('test', 520, 'a');
         $this->createHandler();
-        $this->handler->setHighPriorityLevel(Logger::EMERGENCY); // skip priority notifications
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, $message));
+        $this->handler->setHighPriorityLevel(Level::Emergency); // skip priority notifications
+        $this->handler->handle($this->getRecord(Level::Critical, $message));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -84,7 +84,7 @@ class PushoverHandlerTest extends TestCase
     public function testWriteWithHighPriority()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -94,7 +94,7 @@ class PushoverHandlerTest extends TestCase
     public function testWriteWithEmergencyPriority()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::EMERGENCY, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Emergency, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -104,7 +104,7 @@ class PushoverHandlerTest extends TestCase
     public function testWriteToMultipleUsers()
     {
         $this->createHandler('myToken', ['userA', 'userB']);
-        $this->handler->handle($this->getRecord(Logger::EMERGENCY, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Emergency, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
diff --git a/tests/Monolog/Handler/RedisHandlerTest.php b/tests/Monolog/Handler/RedisHandlerTest.php
index 7ee409a1..c65885c7 100644
--- a/tests/Monolog/Handler/RedisHandlerTest.php
+++ b/tests/Monolog/Handler/RedisHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\LineFormatter;
 
 class RedisHandlerTest extends TestCase
@@ -46,7 +46,7 @@ class RedisHandlerTest extends TestCase
         $redis->rpush('key', 'test')->shouldBeCalled();
         $redis = $redis->reveal();
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
         $handler = new RedisHandler($redis, 'key');
         $handler->setFormatter(new LineFormatter("%message%"));
@@ -66,7 +66,7 @@ class RedisHandlerTest extends TestCase
             ->method('rPush')
             ->with('key', 'test');
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
         $handler = new RedisHandler($redis, 'key');
         $handler->setFormatter(new LineFormatter("%message%"));
@@ -98,9 +98,9 @@ class RedisHandlerTest extends TestCase
             ->method('exec')
             ->will($this->returnSelf());
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
-        $handler = new RedisHandler($redis, 'key', Logger::DEBUG, true, 10);
+        $handler = new RedisHandler($redis, 'key', Level::Debug, true, 10);
         $handler->setFormatter(new LineFormatter("%message%"));
         $handler->handle($record);
     }
@@ -129,9 +129,9 @@ class RedisHandlerTest extends TestCase
                 $cb($redisTransaction);
             }));
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass, 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass, 'foo' => 34]);
 
-        $handler = new RedisHandler($redis, 'key', Logger::DEBUG, true, 10);
+        $handler = new RedisHandler($redis, 'key', Level::Debug, true, 10);
         $handler->setFormatter(new LineFormatter("%message%"));
         $handler->handle($record);
     }
diff --git a/tests/Monolog/Handler/RedisPubSubHandlerTest.php b/tests/Monolog/Handler/RedisPubSubHandlerTest.php
index 5a37d410..f3e9f6e6 100644
--- a/tests/Monolog/Handler/RedisPubSubHandlerTest.php
+++ b/tests/Monolog/Handler/RedisPubSubHandlerTest.php
@@ -14,7 +14,7 @@ declare(strict_types=1);
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\LineFormatter;
 
 class RedisPubSubHandlerTest extends TestCase
@@ -48,7 +48,7 @@ class RedisPubSubHandlerTest extends TestCase
         $redis->publish('key', 'test')->shouldBeCalled();
         $redis = $redis->reveal();
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass(), 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass(), 'foo' => 34]);
 
         $handler = new RedisPubSubHandler($redis, 'key');
         $handler->setFormatter(new LineFormatter("%message%"));
@@ -67,7 +67,7 @@ class RedisPubSubHandlerTest extends TestCase
             ->method('publish')
             ->with('key', 'test');
 
-        $record = $this->getRecord(Logger::WARNING, 'test', ['data' => new \stdClass(), 'foo' => 34]);
+        $record = $this->getRecord(Level::Warning, 'test', ['data' => new \stdClass(), 'foo' => 34]);
 
         $handler = new RedisPubSubHandler($redis, 'key');
         $handler->setFormatter(new LineFormatter("%message%"));
diff --git a/tests/Monolog/Handler/RollbarHandlerTest.php b/tests/Monolog/Handler/RollbarHandlerTest.php
index 0aa7cbff..da267a87 100644
--- a/tests/Monolog/Handler/RollbarHandlerTest.php
+++ b/tests/Monolog/Handler/RollbarHandlerTest.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Exception;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use PHPUnit\Framework\MockObject\MockObject;
 use Rollbar\RollbarLogger;
 
@@ -52,7 +52,7 @@ class RollbarHandlerTest extends TestCase
     {
         $handler = $this->createHandler();
 
-        $handler->handle($this->createExceptionRecord(Logger::DEBUG));
+        $handler->handle($this->createExceptionRecord(Level::Debug));
 
         $this->assertEquals('debug', $this->reportedExceptionArguments['payload']['level']);
     }
@@ -79,10 +79,10 @@ class RollbarHandlerTest extends TestCase
 
     private function createHandler(): RollbarHandler
     {
-        return new RollbarHandler($this->rollbarLogger, Logger::DEBUG);
+        return new RollbarHandler($this->rollbarLogger, Level::Debug);
     }
 
-    private function createExceptionRecord($level = Logger::DEBUG, $message = 'test', $exception = null): array
+    private function createExceptionRecord($level = Level::Debug, $message = 'test', $exception = null): array
     {
         return $this->getRecord($level, $message, [
             'exception' => $exception ?: new Exception(),
diff --git a/tests/Monolog/Handler/Slack/SlackRecordTest.php b/tests/Monolog/Handler/Slack/SlackRecordTest.php
index 563bec72..e6c88fe0 100644
--- a/tests/Monolog/Handler/Slack/SlackRecordTest.php
+++ b/tests/Monolog/Handler/Slack/SlackRecordTest.php
@@ -11,7 +11,8 @@
 
 namespace Monolog\Handler\Slack;
 
-use Monolog\Logger;
+use Monolog\Level;
+use Monolog\LevelName;
 use Monolog\Test\TestCase;
 
 /**
@@ -22,24 +23,22 @@ class SlackRecordTest extends TestCase
     public function dataGetAttachmentColor()
     {
         return array(
-            array(Logger::DEBUG, SlackRecord::COLOR_DEFAULT),
-            array(Logger::INFO, SlackRecord::COLOR_GOOD),
-            array(Logger::NOTICE, SlackRecord::COLOR_GOOD),
-            array(Logger::WARNING, SlackRecord::COLOR_WARNING),
-            array(Logger::ERROR, SlackRecord::COLOR_DANGER),
-            array(Logger::CRITICAL, SlackRecord::COLOR_DANGER),
-            array(Logger::ALERT, SlackRecord::COLOR_DANGER),
-            array(Logger::EMERGENCY, SlackRecord::COLOR_DANGER),
+            array(Level::Debug, SlackRecord::COLOR_DEFAULT),
+            array(Level::Info, SlackRecord::COLOR_GOOD),
+            array(Level::Notice, SlackRecord::COLOR_GOOD),
+            array(Level::Warning, SlackRecord::COLOR_WARNING),
+            array(Level::Error, SlackRecord::COLOR_DANGER),
+            array(Level::Critical, SlackRecord::COLOR_DANGER),
+            array(Level::Alert, SlackRecord::COLOR_DANGER),
+            array(Level::Emergency, SlackRecord::COLOR_DANGER),
         );
     }
 
     /**
      * @dataProvider dataGetAttachmentColor
-     * @param int    $logLevel
-     * @param string $expectedColour RGB hex color or name of Slack color
      * @covers ::getAttachmentColor
      */
-    public function testGetAttachmentColor($logLevel, $expectedColour)
+    public function testGetAttachmentColor(Level $logLevel, string $expectedColour)
     {
         $slackRecord = new SlackRecord();
         $this->assertSame(
@@ -155,7 +154,7 @@ class SlackRecordTest extends TestCase
     {
         $message = 'Test message';
         $record = new SlackRecord(null, null, false);
-        $data = $record->getSlackData($this->getRecord(Logger::WARNING, $message));
+        $data = $record->getSlackData($this->getRecord(Level::Warning, $message));
 
         $this->assertArrayHasKey('text', $data);
         $this->assertSame($message, $data['text']);
@@ -181,13 +180,13 @@ class SlackRecordTest extends TestCase
 
         $message = 'Test message';
         $record = new SlackRecord(null, null, false, null, false, false, array(), $formatter);
-        $data = $record->getSlackData($this->getRecord(Logger::WARNING, $message));
+        $data = $record->getSlackData($this->getRecord(Level::Warning, $message));
 
         $this->assertArrayHasKey('text', $data);
         $this->assertSame($message . 'test', $data['text']);
 
         $record->setFormatter($formatter2);
-        $data = $record->getSlackData($this->getRecord(Logger::WARNING, $message));
+        $data = $record->getSlackData($this->getRecord(Level::Warning, $message));
 
         $this->assertArrayHasKey('text', $data);
         $this->assertSame($message . 'test1', $data['text']);
@@ -197,7 +196,7 @@ class SlackRecordTest extends TestCase
     {
         $message = 'Test message';
         $record = new SlackRecord(null);
-        $data = $record->getSlackData($this->getRecord(Logger::WARNING, $message));
+        $data = $record->getSlackData($this->getRecord(Level::Warning, $message));
 
         $this->assertSame($message, $data['attachments'][0]['text']);
         $this->assertSame($message, $data['attachments'][0]['fallback']);
@@ -206,11 +205,11 @@ class SlackRecordTest extends TestCase
     public function testMapsLevelToColorAttachmentColor()
     {
         $record = new SlackRecord(null);
-        $errorLoggerRecord = $this->getRecord(Logger::ERROR);
-        $emergencyLoggerRecord = $this->getRecord(Logger::EMERGENCY);
-        $warningLoggerRecord = $this->getRecord(Logger::WARNING);
-        $infoLoggerRecord = $this->getRecord(Logger::INFO);
-        $debugLoggerRecord = $this->getRecord(Logger::DEBUG);
+        $errorLoggerRecord = $this->getRecord(Level::Error);
+        $emergencyLoggerRecord = $this->getRecord(Level::Emergency);
+        $warningLoggerRecord = $this->getRecord(Level::Warning);
+        $infoLoggerRecord = $this->getRecord(Level::Info);
+        $debugLoggerRecord = $this->getRecord(Level::Debug);
 
         $data = $record->getSlackData($errorLoggerRecord);
         $this->assertSame(SlackRecord::COLOR_DANGER, $data['attachments'][0]['color']);
@@ -230,8 +229,8 @@ class SlackRecordTest extends TestCase
 
     public function testAddsShortAttachmentWithoutContextAndExtra()
     {
-        $level = Logger::ERROR;
-        $levelName = Logger::getLevelName($level);
+        $level = Level::Error;
+        $levelName = LevelName::fromLevel($level)->value;
         $record = new SlackRecord(null, null, true, null, true);
         $data = $record->getSlackData($this->getRecord($level, 'test', array('test' => 1)));
 
@@ -244,8 +243,8 @@ class SlackRecordTest extends TestCase
 
     public function testAddsShortAttachmentWithContextAndExtra()
     {
-        $level = Logger::ERROR;
-        $levelName = Logger::getLevelName($level);
+        $level = Level::Error;
+        $levelName = LevelName::fromLevel($level)->value;
         $context = array('test' => 1);
         $extra = array('tags' => array('web'));
         $record = new SlackRecord(null, null, true, null, true, true);
@@ -277,8 +276,8 @@ class SlackRecordTest extends TestCase
 
     public function testAddsLongAttachmentWithoutContextAndExtra()
     {
-        $level = Logger::ERROR;
-        $levelName = Logger::getLevelName($level);
+        $level = Level::Error;
+        $levelName = LevelName::fromLevel($level)->value;
         $record = new SlackRecord(null, null, true, null);
         $data = $record->getSlackData($this->getRecord($level, 'test', array('test' => 1)));
 
@@ -299,8 +298,8 @@ class SlackRecordTest extends TestCase
 
     public function testAddsLongAttachmentWithContextAndExtra()
     {
-        $level = Logger::ERROR;
-        $levelName = Logger::getLevelName($level);
+        $level = Level::Error;
+        $levelName = LevelName::fromLevel($level)->value;
         $context = array('test' => 1);
         $extra = array('tags' => array('web'));
         $record = new SlackRecord(null, null, true, null, false, true);
@@ -350,7 +349,7 @@ class SlackRecordTest extends TestCase
 
     public function testContextHasException()
     {
-        $record = $this->getRecord(Logger::CRITICAL, 'This is a critical message.', array('exception' => new \Exception()));
+        $record = $this->getRecord(Level::Critical, 'This is a critical message.', array('exception' => new \Exception()));
         $slackRecord = new SlackRecord(null, null, true, null, false, true);
         $data = $slackRecord->getSlackData($record);
         $this->assertIsString($data['attachments'][0]['fields'][1]['value']);
@@ -359,7 +358,7 @@ class SlackRecordTest extends TestCase
     public function testExcludeExtraAndContextFields()
     {
         $record = $this->getRecord(
-            Logger::WARNING,
+            Level::Warning,
             'test',
             context: array('info' => array('library' => 'monolog', 'author' => 'Jordi')),
             extra: array('tags' => array('web', 'cli')),
diff --git a/tests/Monolog/Handler/SlackHandlerTest.php b/tests/Monolog/Handler/SlackHandlerTest.php
index c6252513..45b439dd 100644
--- a/tests/Monolog/Handler/SlackHandlerTest.php
+++ b/tests/Monolog/Handler/SlackHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\LineFormatter;
 use Monolog\Handler\Slack\SlackRecord;
 
@@ -42,7 +42,7 @@ class SlackHandlerTest extends TestCase
     public function testWriteHeader()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -52,7 +52,7 @@ class SlackHandlerTest extends TestCase
     public function testWriteContent()
     {
         $this->createHandler();
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -65,13 +65,13 @@ class SlackHandlerTest extends TestCase
     public function testWriteContentUsesFormatterIfProvided()
     {
         $this->createHandler('myToken', 'channel1', 'Monolog', false);
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
         $this->createHandler('myToken', 'channel1', 'Monolog', false);
         $this->handler->setFormatter(new LineFormatter('foo--%message%'));
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test2'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test2'));
         fseek($this->res, 0);
         $content2 = fread($this->res, 1024);
 
@@ -82,7 +82,7 @@ class SlackHandlerTest extends TestCase
     public function testWriteContentWithEmoji()
     {
         $this->createHandler('myToken', 'channel1', 'Monolog', true, 'alien');
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -105,7 +105,7 @@ class SlackHandlerTest extends TestCase
     public function testWriteContentWithPlainTextMessage()
     {
         $this->createHandler('myToken', 'channel1', 'Monolog', false);
-        $this->handler->handle($this->getRecord(Logger::CRITICAL, 'test1'));
+        $this->handler->handle($this->getRecord(Level::Critical, 'test1'));
         fseek($this->res, 0);
         $content = fread($this->res, 1024);
 
@@ -115,20 +115,20 @@ class SlackHandlerTest extends TestCase
     public function provideLevelColors()
     {
         return array(
-            array(Logger::DEBUG,    urlencode(SlackRecord::COLOR_DEFAULT)),
-            array(Logger::INFO,     SlackRecord::COLOR_GOOD),
-            array(Logger::NOTICE,   SlackRecord::COLOR_GOOD),
-            array(Logger::WARNING,  SlackRecord::COLOR_WARNING),
-            array(Logger::ERROR,    SlackRecord::COLOR_DANGER),
-            array(Logger::CRITICAL, SlackRecord::COLOR_DANGER),
-            array(Logger::ALERT,    SlackRecord::COLOR_DANGER),
-            array(Logger::EMERGENCY,SlackRecord::COLOR_DANGER),
+            array(Level::Debug,    urlencode(SlackRecord::COLOR_DEFAULT)),
+            array(Level::Info,     SlackRecord::COLOR_GOOD),
+            array(Level::Notice,   SlackRecord::COLOR_GOOD),
+            array(Level::Warning,  SlackRecord::COLOR_WARNING),
+            array(Level::Error,    SlackRecord::COLOR_DANGER),
+            array(Level::Critical, SlackRecord::COLOR_DANGER),
+            array(Level::Alert,    SlackRecord::COLOR_DANGER),
+            array(Level::Emergency,SlackRecord::COLOR_DANGER),
         );
     }
 
     private function createHandler($token = 'myToken', $channel = 'channel1', $username = 'Monolog', $useAttachment = true, $iconEmoji = null, $useShortAttachment = false, $includeExtra = false)
     {
-        $constructorArgs = [$token, $channel, $username, $useAttachment, $iconEmoji, Logger::DEBUG, true, $useShortAttachment, $includeExtra];
+        $constructorArgs = [$token, $channel, $username, $useAttachment, $iconEmoji, Level::Debug, true, $useShortAttachment, $includeExtra];
         $this->res = fopen('php://memory', 'a');
         $this->handler = $this->getMockBuilder('Monolog\Handler\SlackHandler')
             ->setConstructorArgs($constructorArgs)
diff --git a/tests/Monolog/Handler/SlackWebhookHandlerTest.php b/tests/Monolog/Handler/SlackWebhookHandlerTest.php
index 5ff26225..2dfb5444 100644
--- a/tests/Monolog/Handler/SlackWebhookHandlerTest.php
+++ b/tests/Monolog/Handler/SlackWebhookHandlerTest.php
@@ -11,8 +11,9 @@
 
 namespace Monolog\Handler;
 
+use Monolog\LevelName;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Formatter\LineFormatter;
 use Monolog\Handler\Slack\SlackRecord;
 
@@ -72,7 +73,7 @@ class SlackWebhookHandlerTest extends TestCase
             ':ghost:',
             false,
             false,
-            Logger::DEBUG,
+            Level::Debug,
             false
         );
 
@@ -100,7 +101,7 @@ class SlackWebhookHandlerTest extends TestCase
             'https://www.example.com/example.png',
             false,
             false,
-            Logger::DEBUG,
+            Level::Debug,
             false
         );
 
@@ -118,7 +119,7 @@ class SlackWebhookHandlerTest extends TestCase
                     'fields' => array(
                         array(
                             'title' => 'Level',
-                            'value' => Logger::getLevelName(Logger::WARNING),
+                            'value' => LevelName::Warning->value,
                             'short' => false,
                         ),
                     ),
diff --git a/tests/Monolog/Handler/SocketHandlerTest.php b/tests/Monolog/Handler/SocketHandlerTest.php
index 272dd704..ddc7597a 100644
--- a/tests/Monolog/Handler/SocketHandlerTest.php
+++ b/tests/Monolog/Handler/SocketHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 use PHPUnit\Framework\MockObject\MockObject;
 
 /**
@@ -285,7 +285,7 @@ class SocketHandlerTest extends TestCase
 
     private function writeRecord($string)
     {
-        $this->handler->handle($this->getRecord(Logger::WARNING, $string));
+        $this->handler->handle($this->getRecord(Level::Warning, $string));
     }
 
     private function setMockHandler(array $methods = [])
diff --git a/tests/Monolog/Handler/StreamHandlerTest.php b/tests/Monolog/Handler/StreamHandlerTest.php
index 97d56b8c..c0f4979f 100644
--- a/tests/Monolog/Handler/StreamHandlerTest.php
+++ b/tests/Monolog/Handler/StreamHandlerTest.php
@@ -13,7 +13,7 @@ namespace Monolog\Handler;
 
 use Monolog\Handler\StreamHandler;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class StreamHandlerTest extends TestCase
 {
@@ -26,9 +26,9 @@ class StreamHandlerTest extends TestCase
         $handle = fopen('php://memory', 'a+');
         $handler = new StreamHandler($handle);
         $handler->setFormatter($this->getIdentityFormatter());
-        $handler->handle($this->getRecord(Logger::WARNING, 'test'));
-        $handler->handle($this->getRecord(Logger::WARNING, 'test2'));
-        $handler->handle($this->getRecord(Logger::WARNING, 'test3'));
+        $handler->handle($this->getRecord(Level::Warning, 'test'));
+        $handler->handle($this->getRecord(Level::Warning, 'test2'));
+        $handler->handle($this->getRecord(Level::Warning, 'test3'));
         fseek($handle, 0);
         $this->assertEquals('testtest2test3', fread($handle, 100));
     }
@@ -51,7 +51,7 @@ class StreamHandlerTest extends TestCase
     public function testClose()
     {
         $handler = new StreamHandler('php://memory');
-        $handler->handle($this->getRecord(Logger::WARNING, 'test'));
+        $handler->handle($this->getRecord(Level::Warning, 'test'));
         $stream = $handler->getStream();
 
         $this->assertTrue(is_resource($stream));
@@ -66,7 +66,7 @@ class StreamHandlerTest extends TestCase
     public function testSerialization()
     {
         $handler = new StreamHandler('php://memory');
-        $handler->handle($this->getRecord(Logger::WARNING, 'testfoo'));
+        $handler->handle($this->getRecord(Level::Warning, 'testfoo'));
         $stream = $handler->getStream();
 
         $this->assertTrue(is_resource($stream));
@@ -76,7 +76,7 @@ class StreamHandlerTest extends TestCase
         $this->assertFalse(is_resource($stream));
 
         $handler = unserialize($serialized);
-        $handler->handle($this->getRecord(Logger::WARNING, 'testbar'));
+        $handler->handle($this->getRecord(Level::Warning, 'testbar'));
         $stream = $handler->getStream();
 
         $this->assertTrue(is_resource($stream));
@@ -102,7 +102,7 @@ class StreamHandlerTest extends TestCase
     public function testWriteLocking()
     {
         $temp = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'monolog_locked_log';
-        $handler = new StreamHandler($temp, Logger::DEBUG, true, null, true);
+        $handler = new StreamHandler($temp, Level::Debug, true, null, true);
         $handler->handle($this->getRecord());
     }
 
diff --git a/tests/Monolog/Handler/SyslogHandlerTest.php b/tests/Monolog/Handler/SyslogHandlerTest.php
index 5479d547..18fb2bcb 100644
--- a/tests/Monolog/Handler/SyslogHandlerTest.php
+++ b/tests/Monolog/Handler/SyslogHandlerTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 
 class SyslogHandlerTest extends \PHPUnit\Framework\TestCase
 {
@@ -29,7 +29,7 @@ class SyslogHandlerTest extends \PHPUnit\Framework\TestCase
         $handler = new SyslogHandler('test', 'user');
         $this->assertInstanceOf('Monolog\Handler\SyslogHandler', $handler);
 
-        $handler = new SyslogHandler('test', LOG_USER, Logger::DEBUG, true, LOG_PERROR);
+        $handler = new SyslogHandler('test', LOG_USER, Level::Debug, true, LOG_PERROR);
         $this->assertInstanceOf('Monolog\Handler\SyslogHandler', $handler);
     }
 
diff --git a/tests/Monolog/Handler/SyslogUdpHandlerTest.php b/tests/Monolog/Handler/SyslogUdpHandlerTest.php
index 7cb83254..530a9d53 100644
--- a/tests/Monolog/Handler/SyslogUdpHandlerTest.php
+++ b/tests/Monolog/Handler/SyslogUdpHandlerTest.php
@@ -11,6 +11,7 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 /**
@@ -98,6 +99,6 @@ class SyslogUdpHandlerTest extends TestCase
 
     protected function getRecordWithMessage($msg)
     {
-        return $this->getRecord(message: $msg, level: \Monolog\Logger::WARNING, channel: 'lol', datetime: new \DateTimeImmutable('2014-01-07 12:34:56'));
+        return $this->getRecord(message: $msg, level: Level::Warning, channel: 'lol', datetime: new \DateTimeImmutable('2014-01-07 12:34:56'));
     }
 }
diff --git a/tests/Monolog/Handler/TelegramBotHandlerTest.php b/tests/Monolog/Handler/TelegramBotHandlerTest.php
index 6cb3c7d9..754af333 100644
--- a/tests/Monolog/Handler/TelegramBotHandlerTest.php
+++ b/tests/Monolog/Handler/TelegramBotHandlerTest.php
@@ -11,7 +11,7 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 
 /**
@@ -42,7 +42,7 @@ class TelegramBotHandlerTest extends TestCase
         bool $disableWebPagePreview = false,
         bool $disableNotification = true
     ): void {
-        $constructorArgs = [$apiKey, $channel, Logger::DEBUG, true, $parseMode, $disableWebPagePreview, $disableNotification];
+        $constructorArgs = [$apiKey, $channel, Level::Debug, true, $parseMode, $disableWebPagePreview, $disableNotification];
 
         $this->handler = $this->getMockBuilder(TelegramBotHandler::class)
             ->setConstructorArgs($constructorArgs)
diff --git a/tests/Monolog/Handler/TestHandlerTest.php b/tests/Monolog/Handler/TestHandlerTest.php
index b4609c92..218d111c 100644
--- a/tests/Monolog/Handler/TestHandlerTest.php
+++ b/tests/Monolog/Handler/TestHandlerTest.php
@@ -11,8 +11,8 @@
 
 namespace Monolog\Handler;
 
+use Monolog\Level;
 use Monolog\Test\TestCase;
-use Monolog\Logger;
 
 /**
  * @covers Monolog\Handler\TestHandler
@@ -22,7 +22,7 @@ class TestHandlerTest extends TestCase
     /**
      * @dataProvider methodProvider
      */
-    public function testHandler($method, $level)
+    public function testHandler($method, Level $level)
     {
         $handler = new TestHandler;
         $record = $this->getRecord($level, 'test'.$method);
@@ -57,7 +57,7 @@ class TestHandlerTest extends TestCase
     public function testHandlerAssertEmptyContext()
     {
         $handler = new TestHandler;
-        $record  = $this->getRecord(Logger::WARNING, 'test', []);
+        $record  = $this->getRecord(Level::Warning, 'test', []);
         $this->assertFalse($handler->hasWarning([
             'message' => 'test',
             'context' => [],
@@ -80,7 +80,7 @@ class TestHandlerTest extends TestCase
     public function testHandlerAssertNonEmptyContext()
     {
         $handler = new TestHandler;
-        $record  = $this->getRecord(Logger::WARNING, 'test', ['foo' => 'bar']);
+        $record  = $this->getRecord(Level::Warning, 'test', ['foo' => 'bar']);
         $this->assertFalse($handler->hasWarning([
             'message' => 'test',
             'context' => [
@@ -105,14 +105,14 @@ class TestHandlerTest extends TestCase
     public function methodProvider()
     {
         return [
-            ['Emergency', Logger::EMERGENCY],
-            ['Alert'    , Logger::ALERT],
-            ['Critical' , Logger::CRITICAL],
-            ['Error'    , Logger::ERROR],
-            ['Warning'  , Logger::WARNING],
-            ['Info'     , Logger::INFO],
-            ['Notice'   , Logger::NOTICE],
-            ['Debug'    , Logger::DEBUG],
+            ['Emergency', Level::Emergency],
+            ['Alert'    , Level::Alert],
+            ['Critical' , Level::Critical],
+            ['Error'    , Level::Error],
+            ['Warning'  , Level::Warning],
+            ['Info'     , Level::Info],
+            ['Notice'   , Level::Notice],
+            ['Debug'    , Level::Debug],
         ];
     }
 }
diff --git a/tests/Monolog/Handler/WhatFailureGroupHandlerTest.php b/tests/Monolog/Handler/WhatFailureGroupHandlerTest.php
index 3d0d3b12..77bc932b 100644
--- a/tests/Monolog/Handler/WhatFailureGroupHandlerTest.php
+++ b/tests/Monolog/Handler/WhatFailureGroupHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class WhatFailureGroupHandlerTest extends TestCase
 {
@@ -34,8 +34,8 @@ class WhatFailureGroupHandlerTest extends TestCase
     {
         $testHandlers = [new TestHandler(), new TestHandler()];
         $handler = new WhatFailureGroupHandler($testHandlers);
-        $handler->handle($this->getRecord(Logger::DEBUG));
-        $handler->handle($this->getRecord(Logger::INFO));
+        $handler->handle($this->getRecord(Level::Debug));
+        $handler->handle($this->getRecord(Level::Info));
         foreach ($testHandlers as $test) {
             $this->assertTrue($test->hasDebugRecords());
             $this->assertTrue($test->hasInfoRecords());
@@ -50,7 +50,7 @@ class WhatFailureGroupHandlerTest extends TestCase
     {
         $testHandlers = [new TestHandler(), new TestHandler()];
         $handler = new WhatFailureGroupHandler($testHandlers);
-        $handler->handleBatch([$this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO)]);
+        $handler->handleBatch([$this->getRecord(Level::Debug), $this->getRecord(Level::Info)]);
         foreach ($testHandlers as $test) {
             $this->assertTrue($test->hasDebugRecords());
             $this->assertTrue($test->hasInfoRecords());
@@ -63,11 +63,11 @@ class WhatFailureGroupHandlerTest extends TestCase
      */
     public function testIsHandling()
     {
-        $testHandlers = [new TestHandler(Logger::ERROR), new TestHandler(Logger::WARNING)];
+        $testHandlers = [new TestHandler(Level::Error), new TestHandler(Level::Warning)];
         $handler = new WhatFailureGroupHandler($testHandlers);
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::ERROR)));
-        $this->assertTrue($handler->isHandling($this->getRecord(Logger::WARNING)));
-        $this->assertFalse($handler->isHandling($this->getRecord(Logger::DEBUG)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Error)));
+        $this->assertTrue($handler->isHandling($this->getRecord(Level::Warning)));
+        $this->assertFalse($handler->isHandling($this->getRecord(Level::Debug)));
     }
 
     /**
@@ -82,7 +82,7 @@ class WhatFailureGroupHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasWarningRecords());
         $records = $test->getRecords();
         $this->assertTrue($records[0]['extra']['foo']);
@@ -105,7 +105,7 @@ class WhatFailureGroupHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handleBatch(array($this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO)));
+        $handler->handleBatch(array($this->getRecord(Level::Debug), $this->getRecord(Level::Info)));
         foreach ($testHandlers as $test) {
             $this->assertTrue($test->hasDebugRecords());
             $this->assertTrue($test->hasInfoRecords());
@@ -131,7 +131,7 @@ class WhatFailureGroupHandlerTest extends TestCase
 
             return $record;
         });
-        $handler->handle($this->getRecord(Logger::WARNING));
+        $handler->handle($this->getRecord(Level::Warning));
         $this->assertTrue($test->hasWarningRecords());
         $records = $test->getRecords();
         $this->assertTrue($records[0]['extra']['foo']);
diff --git a/tests/Monolog/Handler/ZendMonitorHandlerTest.php b/tests/Monolog/Handler/ZendMonitorHandlerTest.php
index 42622ffb..217a6e55 100644
--- a/tests/Monolog/Handler/ZendMonitorHandlerTest.php
+++ b/tests/Monolog/Handler/ZendMonitorHandlerTest.php
@@ -12,7 +12,7 @@
 namespace Monolog\Handler;
 
 use Monolog\Test\TestCase;
-use Monolog\Logger;
+use Monolog\Level;
 
 class ZendMonitorHandlerTest extends TestCase
 {
@@ -51,15 +51,13 @@ class ZendMonitorHandlerTest extends TestCase
             ->method('getDefaultFormatter')
             ->will($this->returnValue($formatterMock));
 
-        $levelMap = $zendMonitor->getLevelMap();
-
         $zendMonitor->expects($this->once())
             ->method('writeZendMonitorCustomEvent')
             ->with(
-                Logger::getLevelName($record->level),
+                $record->levelName->value,
                 $record->message,
                 $formatterResult,
-                $levelMap[$record->level]
+                \ZEND_MONITOR_EVENT_SEVERITY_WARNING
             );
 
         $zendMonitor->handle($record);
diff --git a/tests/Monolog/LoggerTest.php b/tests/Monolog/LoggerTest.php
index 9ba62f74..70b4a9ff 100644
--- a/tests/Monolog/LoggerTest.php
+++ b/tests/Monolog/LoggerTest.php
@@ -18,7 +18,7 @@ use Monolog\Test\TestCase;
 class LoggerTest extends TestCase
 {
     /**
-     * @covers Monolog\Logger::getName
+     * @covers Logger::getName
      */
     public function testGetName()
     {
@@ -27,15 +27,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::getLevelName
-     */
-    public function testGetLevelName()
-    {
-        $this->assertEquals('ERROR', Logger::getLevelName(Logger::ERROR));
-    }
-
-    /**
-     * @covers Monolog\Logger::withName
+     * @covers Logger::withName
      */
     public function testWithName()
     {
@@ -48,32 +40,22 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::toMonologLevel
+     * @covers Logger::toMonologLevel
      */
     public function testConvertPSR3ToMonologLevel()
     {
-        $this->assertEquals(Logger::toMonologLevel('debug'), 100);
-        $this->assertEquals(Logger::toMonologLevel('info'), 200);
-        $this->assertEquals(Logger::toMonologLevel('notice'), 250);
-        $this->assertEquals(Logger::toMonologLevel('warning'), 300);
-        $this->assertEquals(Logger::toMonologLevel('error'), 400);
-        $this->assertEquals(Logger::toMonologLevel('critical'), 500);
-        $this->assertEquals(Logger::toMonologLevel('alert'), 550);
-        $this->assertEquals(Logger::toMonologLevel('emergency'), 600);
+        $this->assertEquals(Logger::toMonologLevel('debug'), Level::Debug);
+        $this->assertEquals(Logger::toMonologLevel('info'), Level::Info);
+        $this->assertEquals(Logger::toMonologLevel('notice'), Level::Notice);
+        $this->assertEquals(Logger::toMonologLevel('warning'), Level::Warning);
+        $this->assertEquals(Logger::toMonologLevel('error'), Level::Error);
+        $this->assertEquals(Logger::toMonologLevel('critical'), Level::Critical);
+        $this->assertEquals(Logger::toMonologLevel('alert'), Level::Alert);
+        $this->assertEquals(Logger::toMonologLevel('emergency'), Level::Emergency);
     }
 
     /**
-     * @covers Monolog\Logger::getLevelName
-     */
-    public function testGetLevelNameThrows()
-    {
-        $this->expectException(\InvalidArgumentException::class);
-
-        Logger::getLevelName(5);
-    }
-
-    /**
-     * @covers Monolog\Logger::__construct
+     * @covers Logger::__construct
      */
     public function testChannel()
     {
@@ -86,7 +68,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testLog()
     {
@@ -98,11 +80,11 @@ class LoggerTest extends TestCase
 
         $logger->pushHandler($handler);
 
-        $this->assertTrue($logger->addRecord(Logger::WARNING, 'test'));
+        $this->assertTrue($logger->addRecord(Level::Warning, 'test'));
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testLogAlwaysHandledIfNoProcessorsArePresent()
     {
@@ -114,11 +96,11 @@ class LoggerTest extends TestCase
 
         $logger->pushHandler($handler);
 
-        $this->assertTrue($logger->addRecord(Logger::WARNING, 'test'));
+        $this->assertTrue($logger->addRecord(Level::Warning, 'test'));
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testLogNotHandledIfProcessorsArePresent()
     {
@@ -131,7 +113,7 @@ class LoggerTest extends TestCase
         $logger->pushProcessor(fn (LogRecord $record) => $record);
         $logger->pushHandler($handler);
 
-        $this->assertFalse($logger->addRecord(Logger::WARNING, 'test'));
+        $this->assertFalse($logger->addRecord(Level::Warning, 'test'));
     }
 
     public function testHandlersInCtor()
@@ -155,8 +137,8 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::pushHandler
-     * @covers Monolog\Logger::popHandler
+     * @covers Logger::pushHandler
+     * @covers Logger::popHandler
      */
     public function testPushPopHandler()
     {
@@ -176,7 +158,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::setHandlers
+     * @covers Logger::setHandlers
      */
     public function testSetHandlers()
     {
@@ -200,8 +182,8 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::pushProcessor
-     * @covers Monolog\Logger::popProcessor
+     * @covers Logger::pushProcessor
+     * @covers Logger::popProcessor
      */
     public function testPushPopProcessor()
     {
@@ -221,7 +203,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testProcessorsAreExecuted()
     {
@@ -239,7 +221,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testProcessorsAreCalledOnlyOnce()
     {
@@ -270,7 +252,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testProcessorsNotCalledWhenNotHandled()
     {
@@ -289,7 +271,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testHandlersNotCalledBeforeFirstHandlingWhenProcessorsPresent()
     {
@@ -332,7 +314,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testHandlersNotCalledBeforeFirstHandlingWhenProcessorsPresentWithAssocArray()
     {
@@ -372,7 +354,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testBubblingWhenTheHandlerReturnsFalse()
     {
@@ -404,7 +386,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::addRecord
      */
     public function testNotBubblingWhenTheHandlerReturnsTrue()
     {
@@ -435,7 +417,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::isHandling
+     * @covers Logger::isHandling
      */
     public function testIsHandling()
     {
@@ -448,7 +430,7 @@ class LoggerTest extends TestCase
         ;
 
         $logger->pushHandler($handler1);
-        $this->assertFalse($logger->isHandling(Logger::DEBUG));
+        $this->assertFalse($logger->isHandling(Level::Debug));
 
         $handler2 = $this->createMock('Monolog\Handler\HandlerInterface');
         $handler2->expects($this->any())
@@ -457,21 +439,21 @@ class LoggerTest extends TestCase
         ;
 
         $logger->pushHandler($handler2);
-        $this->assertTrue($logger->isHandling(Logger::DEBUG));
+        $this->assertTrue($logger->isHandling(Level::Debug));
     }
 
     /**
      * @dataProvider logMethodProvider
-     * @covers Monolog\Logger::debug
-     * @covers Monolog\Logger::info
-     * @covers Monolog\Logger::notice
-     * @covers Monolog\Logger::warning
-     * @covers Monolog\Logger::error
-     * @covers Monolog\Logger::critical
-     * @covers Monolog\Logger::alert
-     * @covers Monolog\Logger::emergency
+     * @covers Level::Debug
+     * @covers Level::Info
+     * @covers Level::Notice
+     * @covers Level::Warning
+     * @covers Level::Error
+     * @covers Level::Critical
+     * @covers Level::Alert
+     * @covers Level::Emergency
      */
-    public function testLogMethods($method, $expectedLevel)
+    public function testLogMethods(string $method, Level $expectedLevel)
     {
         $logger = new Logger('foo');
         $handler = new TestHandler;
@@ -485,20 +467,20 @@ class LoggerTest extends TestCase
     {
         return [
             // PSR-3 methods
-            ['debug',  Logger::DEBUG],
-            ['info',   Logger::INFO],
-            ['notice', Logger::NOTICE],
-            ['warning',   Logger::WARNING],
-            ['error',    Logger::ERROR],
-            ['critical',   Logger::CRITICAL],
-            ['alert',  Logger::ALERT],
-            ['emergency',  Logger::EMERGENCY],
+            ['debug',  Level::Debug],
+            ['info',   Level::Info],
+            ['notice', Level::Notice],
+            ['warning',   Level::Warning],
+            ['error',    Level::Error],
+            ['critical',   Level::Critical],
+            ['alert',  Level::Alert],
+            ['emergency',  Level::Emergency],
         ];
     }
 
     /**
      * @dataProvider setTimezoneProvider
-     * @covers Monolog\Logger::setTimezone
+     * @covers Logger::setTimezone
      */
     public function testSetTimezone($tz)
     {
@@ -522,8 +504,8 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::setTimezone
-     * @covers Monolog\DateTimeImmutable::__construct
+     * @covers Logger::setTimezone
+     * @covers DateTimeImmutable::__construct
      */
     public function testTimezoneIsRespectedInUTC()
     {
@@ -544,8 +526,8 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::setTimezone
-     * @covers Monolog\DateTimeImmutable::__construct
+     * @covers Logger::setTimezone
+     * @covers DateTimeImmutable::__construct
      */
     public function testTimezoneIsRespectedInOtherTimezone()
     {
@@ -573,8 +555,8 @@ class LoggerTest extends TestCase
 
     /**
      * @dataProvider useMicrosecondTimestampsProvider
-     * @covers Monolog\Logger::useMicrosecondTimestamps
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::useMicrosecondTimestamps
+     * @covers Logger::addRecord
      */
     public function testUseMicrosecondTimestamps($micro, $assert, $assertFormat)
     {
@@ -603,7 +585,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::setExceptionHandler
+     * @covers Logger::setExceptionHandler
      */
     public function testSetExceptionHandler()
     {
@@ -616,7 +598,7 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::handleException
+     * @covers Logger::handleException
      */
     public function testDefaultHandleException()
     {
@@ -638,8 +620,8 @@ class LoggerTest extends TestCase
     }
 
     /**
-     * @covers Monolog\Logger::handleException
-     * @covers Monolog\Logger::addRecord
+     * @covers Logger::handleException
+     * @covers Logger::addRecord
      */
     public function testCustomHandleException()
     {
@@ -689,13 +671,12 @@ class LoggerTest extends TestCase
 
             return $reflectionProperty->getValue($object);
         };
-        $that = $this;
-        $assertBufferOfBufferHandlerEmpty = function () use ($getProperty, $bufferHandler, $that) {
-            $that->assertEmpty($getProperty($bufferHandler, 'buffer'));
+        $assertBufferOfBufferHandlerEmpty = function () use ($getProperty, $bufferHandler) {
+            self::assertEmpty($getProperty($bufferHandler, 'buffer'));
         };
-        $assertBuffersEmpty = function () use ($assertBufferOfBufferHandlerEmpty, $getProperty, $fingersCrossedHandler, $that) {
+        $assertBuffersEmpty = function () use ($assertBufferOfBufferHandlerEmpty, $getProperty, $fingersCrossedHandler) {
             $assertBufferOfBufferHandlerEmpty();
-            $that->assertEmpty($getProperty($fingersCrossedHandler, 'buffer'));
+            self::assertEmpty($getProperty($fingersCrossedHandler, 'buffer'));
         };
 
         $logger->debug('debug1');
@@ -710,8 +691,8 @@ class LoggerTest extends TestCase
         $logger->error('error2');
         $logger->reset();
         $assertBuffersEmpty();
-        $this->assertTrue($testHandler->hasRecordThatContains('debug2', Logger::DEBUG));
-        $this->assertTrue($testHandler->hasRecordThatContains('error2', Logger::ERROR));
+        $this->assertTrue($testHandler->hasRecordThatContains('debug2', Level::Debug));
+        $this->assertTrue($testHandler->hasRecordThatContains('error2', Level::Error));
         $this->assertNotSame($uid1, $uid1 = $processorUid1->getUid());
         $this->assertNotSame($uid2, $uid2 = $processorUid2->getUid());
 
@@ -731,8 +712,8 @@ class LoggerTest extends TestCase
         $logger->reset();
         $assertBuffersEmpty();
         $this->assertFalse($testHandler->hasInfoRecords());
-        $this->assertTrue($testHandler->hasRecordThatContains('notice4', Logger::NOTICE));
-        $this->assertTrue($testHandler->hasRecordThatContains('emergency4', Logger::EMERGENCY));
+        $this->assertTrue($testHandler->hasRecordThatContains('notice4', Level::Notice));
+        $this->assertTrue($testHandler->hasRecordThatContains('emergency4', Level::Emergency));
         $this->assertNotSame($uid1, $processorUid1->getUid());
         $this->assertNotSame($uid2, $processorUid2->getUid());
     }
diff --git a/tests/Monolog/Processor/IntrospectionProcessorTest.php b/tests/Monolog/Processor/IntrospectionProcessorTest.php
index ac5b523d..d18dbd00 100644
--- a/tests/Monolog/Processor/IntrospectionProcessorTest.php
+++ b/tests/Monolog/Processor/IntrospectionProcessorTest.php
@@ -26,7 +26,7 @@ function tester($handler, $record)
 
 namespace Monolog\Processor;
 
-use Monolog\Logger;
+use Monolog\Level;
 use Monolog\Test\TestCase;
 use Monolog\Handler\TestHandler;
 
@@ -66,11 +66,11 @@ class IntrospectionProcessorTest extends TestCase
 
     public function testLevelTooLow()
     {
-        $input = $this->getRecord(Logger::DEBUG);
+        $input = $this->getRecord(Level::Debug);
 
         $expected = $input;
 
-        $processor = new IntrospectionProcessor(Logger::CRITICAL);
+        $processor = new IntrospectionProcessor(Level::Critical);
         $actual = $processor($input);
 
         $this->assertEquals($expected, $actual);
@@ -78,7 +78,7 @@ class IntrospectionProcessorTest extends TestCase
 
     public function testLevelEqual()
     {
-        $input = $this->getRecord(Logger::CRITICAL);
+        $input = $this->getRecord(Level::Critical);
 
         $expected = $input;
         $expected['extra'] = [
@@ -89,7 +89,7 @@ class IntrospectionProcessorTest extends TestCase
             'callType' => '->',
         ];
 
-        $processor = new IntrospectionProcessor(Logger::CRITICAL);
+        $processor = new IntrospectionProcessor(Level::Critical);
         $actual = $processor($input);
 
         $this->assertEquals($expected, $actual);
@@ -97,7 +97,7 @@ class IntrospectionProcessorTest extends TestCase
 
     public function testLevelHigher()
     {
-        $input = $this->getRecord(Logger::EMERGENCY);
+        $input = $this->getRecord(Level::Emergency);
 
         $expected = $input;
         $expected['extra'] = [
@@ -108,7 +108,7 @@ class IntrospectionProcessorTest extends TestCase
             'callType' => '->',
         ];
 
-        $processor = new IntrospectionProcessor(Logger::CRITICAL);
+        $processor = new IntrospectionProcessor(Level::Critical);
         $actual = $processor($input);
 
         $this->assertEquals($expected, $actual);