diff --git a/.php_cs b/.php_cs
index b16a35e5..34eb329f 100644
--- a/.php_cs
+++ b/.php_cs
@@ -19,11 +19,14 @@ $finder = PhpCsFixer\Finder::create()
 
 return PhpCsFixer\Config::create()
     ->setUsingCache(true)
-    //->setUsingLinter(false)
     ->setRiskyAllowed(true)
     ->setRules(array(
         '@PSR2' => true,
-        'binary_operator_spaces' => true,
+        // some rules disabled as long as 1.x branch is maintained
+        'binary_operator_spaces' => array(
+            'align_double_arrow' => null,
+            'align_equals' => null,
+        ),
         'blank_line_before_return' => true,
         'cast_spaces' => true,
         'header_comment' => array('header' => $header),
@@ -31,29 +34,29 @@ return PhpCsFixer\Config::create()
         'method_separation' => true,
         'no_blank_lines_after_class_opening' => true,
         'no_blank_lines_after_phpdoc' => true,
-        'no_blank_lines_between_uses' => true,
         'no_empty_statement' => true,
         'no_extra_consecutive_blank_lines' => true,
         'no_leading_import_slash' => true,
         'no_leading_namespace_whitespace' => true,
         'no_trailing_comma_in_singleline_array' => true,
         'no_unused_imports' => true,
-        'no_whitespace_in_blank_lines' => true,
+        'no_whitespace_in_blank_line' => true,
         'object_operator_without_whitespace' => true,
         'phpdoc_align' => true,
         'phpdoc_indent' => true,
         'phpdoc_no_access' => true,
         'phpdoc_no_package' => true,
         'phpdoc_order' => true,
-        'phpdoc_scalar' => true,
+        //'phpdoc_scalar' => true,
         'phpdoc_trim' => true,
-        'phpdoc_type_to_var' => true,
+        //'phpdoc_types' => true,
         'psr0' => true,
-        'short_array_syntax' => true,
+        //'array_syntax' => array('syntax' => 'short'),
+        'declare_strict_types' => true,
         'single_blank_line_before_namespace' => true,
         'standardize_not_equals' => true,
         'ternary_operator_spaces' => true,
         'trailing_comma_in_multiline_array' => true,
     ))
-    ->finder($finder)
+    ->setFinder($finder)
 ;
diff --git a/src/Monolog/Formatter/LineFormatter.php b/src/Monolog/Formatter/LineFormatter.php
index 07f97677..9d4ef1d7 100644
--- a/src/Monolog/Formatter/LineFormatter.php
+++ b/src/Monolog/Formatter/LineFormatter.php
@@ -76,7 +76,6 @@ class LineFormatter extends NormalizerFormatter
             }
         }
 
-
         foreach ($vars['context'] as $var => $val) {
             if (false !== strpos($output, '%context.'.$var.'%')) {
                 $output = str_replace('%context.'.$var.'%', $this->stringify($val), $output);
diff --git a/src/Monolog/Formatter/LogmaticFormatter.php b/src/Monolog/Formatter/LogmaticFormatter.php
index 8684da41..7a75e00f 100644
--- a/src/Monolog/Formatter/LogmaticFormatter.php
+++ b/src/Monolog/Formatter/LogmaticFormatter.php
@@ -18,7 +18,6 @@ namespace Monolog\Formatter;
  */
 class LogmaticFormatter extends JsonFormatter
 {
-
     const MARKERS = ["sourcecode", "php"];
 
     /**
diff --git a/src/Monolog/Formatter/NormalizerFormatter.php b/src/Monolog/Formatter/NormalizerFormatter.php
index 12ee3740..029c97a7 100644
--- a/src/Monolog/Formatter/NormalizerFormatter.php
+++ b/src/Monolog/Formatter/NormalizerFormatter.php
@@ -57,7 +57,7 @@ class NormalizerFormatter implements FormatterInterface
     }
 
     /**
-     * @param mixed $data
+     * @param  mixed                      $data
      * @return int|bool|string|null|array
      */
     protected function normalize($data, int $depth = 0)
diff --git a/src/Monolog/Handler/NoopHandler.php b/src/Monolog/Handler/NoopHandler.php
index 7c7ec03a..8ee2b4c6 100644
--- a/src/Monolog/Handler/NoopHandler.php
+++ b/src/Monolog/Handler/NoopHandler.php
@@ -3,7 +3,7 @@
 /*
  * This file is part of the Monolog package.
  *
- * (c) Roel Harbers <roelharbers@gmail.com>
+ * (c) Jordi Boggiano <j.boggiano@seld.be>
  *
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
@@ -11,8 +11,6 @@
 
 namespace Monolog\Handler;
 
-use Monolog\Logger;
-
 /**
  * No-op
  *
diff --git a/src/Monolog/Handler/PHPConsoleHandler.php b/src/Monolog/Handler/PHPConsoleHandler.php
index 0bc16ee2..71ffbe59 100644
--- a/src/Monolog/Handler/PHPConsoleHandler.php
+++ b/src/Monolog/Handler/PHPConsoleHandler.php
@@ -66,10 +66,10 @@ class PHPConsoleHandler extends AbstractProcessingHandler
     private $connector;
 
     /**
-     * @param  array          $options   See \Monolog\Handler\PHPConsoleHandler::$options for more details
-     * @param  Connector|null $connector Instance of \PhpConsole\Connector class (optional)
-     * @param  int            $level
-     * @param  bool           $bubble
+     * @param  array            $options   See \Monolog\Handler\PHPConsoleHandler::$options for more details
+     * @param  Connector|null   $connector Instance of \PhpConsole\Connector class (optional)
+     * @param  int              $level
+     * @param  bool             $bubble
      * @throws RuntimeException
      */
     public function __construct(array $options = [], Connector $connector = null, $level = Logger::DEBUG, $bubble = true)
diff --git a/src/Monolog/Handler/RavenHandler.php b/src/Monolog/Handler/RavenHandler.php
index 045f236a..1c8e7185 100644
--- a/src/Monolog/Handler/RavenHandler.php
+++ b/src/Monolog/Handler/RavenHandler.php
@@ -222,7 +222,7 @@ class RavenHandler extends AbstractProcessingHandler
     }
 
     /**
-     * @param string $value
+     * @param  string $value
      * @return self
      */
     public function setRelease($value)
diff --git a/src/Monolog/Handler/Slack/SlackRecord.php b/src/Monolog/Handler/Slack/SlackRecord.php
index 38bc838a..f4dd0e8e 100644
--- a/src/Monolog/Handler/Slack/SlackRecord.php
+++ b/src/Monolog/Handler/Slack/SlackRecord.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.
@@ -127,7 +127,7 @@ class SlackRecord
                 'color'     => $this->getAttachmentColor($record['level']),
                 'fields'    => array(),
                 'mrkdwn_in' => array('fields'),
-                'ts'        => $record['datetime']->getTimestamp()
+                'ts'        => $record['datetime']->getTimestamp(),
             );
 
             if ($this->useShortAttachment) {
@@ -137,7 +137,6 @@ class SlackRecord
                 $attachment['fields'][] = $this->generateAttachmentField('Level', $record['level_name']);
             }
 
-
             if ($this->includeContextAndExtra) {
                 foreach (array('extra', 'context') as $key) {
                     if (empty($record[$key])) {
@@ -229,7 +228,7 @@ class SlackRecord
     /**
      * Generates attachment field
      *
-     * @param string $title
+     * @param string       $title
      * @param string|array $value\
      *
      * @return array
@@ -243,7 +242,7 @@ class SlackRecord
         return array(
             'title' => $title,
             'value' => $value,
-            'short' => false
+            'short' => false,
         );
     }
 
diff --git a/src/Monolog/Handler/SlackWebhookHandler.php b/src/Monolog/Handler/SlackWebhookHandler.php
index a66a0eee..e97a3480 100644
--- a/src/Monolog/Handler/SlackWebhookHandler.php
+++ b/src/Monolog/Handler/SlackWebhookHandler.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.
@@ -36,16 +36,16 @@ class SlackWebhookHandler extends AbstractProcessingHandler
     private $slackRecord;
 
     /**
-     * @param  string      $webhookUrl             Slack Webhook URL
-     * @param  string|null $channel                Slack channel (encoded ID or name)
-     * @param  string|null $username               Name of a bot
-     * @param  bool        $useAttachment          Whether the message should be added to Slack as attachment (plain text otherwise)
-     * @param  string|null $iconEmoji              The emoji name to use (or null)
-     * @param  bool        $useShortAttachment     Whether the the context/extra messages added to Slack as attachments are in a short style
-     * @param  bool        $includeContextAndExtra Whether the attachment should include context and extra data
-     * @param  int         $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  array       $excludeFields          Dot separated list of fields to exclude from slack message. E.g. ['context.field1', 'extra.field2']
+     * @param string      $webhookUrl             Slack Webhook URL
+     * @param string|null $channel                Slack channel (encoded ID or name)
+     * @param string|null $username               Name of a bot
+     * @param bool        $useAttachment          Whether the message should be added to Slack as attachment (plain text otherwise)
+     * @param string|null $iconEmoji              The emoji name to use (or null)
+     * @param bool        $useShortAttachment     Whether the the context/extra messages added to Slack as attachments are in a short style
+     * @param bool        $includeContextAndExtra Whether the attachment should include context and extra data
+     * @param int         $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 array       $excludeFields          Dot separated list of fields to exclude from slack message. E.g. ['context.field1', 'extra.field2']
      */
     public function __construct($webhookUrl, $channel = null, $username = null, $useAttachment = true, $iconEmoji = null, $useShortAttachment = false, $includeContextAndExtra = false, $level = Logger::CRITICAL, $bubble = true, array $excludeFields = array())
     {
diff --git a/src/Monolog/Handler/SlackbotHandler.php b/src/Monolog/Handler/SlackbotHandler.php
index baead525..dd2db593 100644
--- a/src/Monolog/Handler/SlackbotHandler.php
+++ b/src/Monolog/Handler/SlackbotHandler.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.
@@ -40,11 +40,11 @@ class SlackbotHandler extends AbstractProcessingHandler
     private $channel;
 
     /**
-     * @param  string $slackTeam Slack team slug
-     * @param  string $token     Slackbot token
-     * @param  string $channel   Slack channel (encoded ID or name)
-     * @param  int    $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 string $slackTeam Slack team slug
+     * @param string $token     Slackbot token
+     * @param string $channel   Slack channel (encoded ID or name)
+     * @param int    $level     The minimum logging level at which this handler will be triggered
+     * @param bool   $bubble    Whether the messages that are handled can bubble up the stack or not
      */
     public function __construct($slackTeam, $token, $channel, $level = Logger::CRITICAL, $bubble = true)
     {
diff --git a/src/Monolog/Handler/StreamHandler.php b/src/Monolog/Handler/StreamHandler.php
index 2d9addfc..5abbc592 100644
--- a/src/Monolog/Handler/StreamHandler.php
+++ b/src/Monolog/Handler/StreamHandler.php
@@ -125,7 +125,7 @@ class StreamHandler extends AbstractProcessingHandler
     /**
      * Write to stream
      * @param resource $stream
-     * @param array $record
+     * @param array    $record
      */
     protected function streamWrite($stream, array $record)
     {
diff --git a/src/Monolog/Logger.php b/src/Monolog/Logger.php
index bfbe20cf..88ecf0dc 100644
--- a/src/Monolog/Logger.php
+++ b/src/Monolog/Logger.php
@@ -397,9 +397,9 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  mixed   $level   The log level
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param mixed  $level   The log level
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function log($level, $message, array $context = [])
     {
@@ -413,8 +413,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function debug($message, array $context = [])
     {
@@ -426,8 +426,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function info($message, array $context = [])
     {
@@ -439,8 +439,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function notice($message, array $context = [])
     {
@@ -452,8 +452,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function warning($message, array $context = [])
     {
@@ -465,8 +465,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function error($message, array $context = [])
     {
@@ -478,8 +478,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function critical($message, array $context = [])
     {
@@ -491,8 +491,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function alert($message, array $context = [])
     {
@@ -504,8 +504,8 @@ class Logger implements LoggerInterface
      *
      * This method allows for compatibility with common interfaces.
      *
-     * @param  string  $message The log message
-     * @param  array   $context The log context
+     * @param string $message The log message
+     * @param array  $context The log context
      */
     public function emergency($message, array $context = [])
     {
diff --git a/src/Monolog/Processor/MercurialProcessor.php b/src/Monolog/Processor/MercurialProcessor.php
index 87f254b3..6ab5bba9 100644
--- a/src/Monolog/Processor/MercurialProcessor.php
+++ b/src/Monolog/Processor/MercurialProcessor.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.
diff --git a/tests/Monolog/ErrorHandlerTest.php b/tests/Monolog/ErrorHandlerTest.php
index 12784f8b..39eb4247 100644
--- a/tests/Monolog/ErrorHandlerTest.php
+++ b/tests/Monolog/ErrorHandlerTest.php
@@ -15,7 +15,6 @@ use Monolog\Handler\TestHandler;
 
 class ErrorHandlerTest extends \PHPUnit_Framework_TestCase
 {
-
     public function testRegister()
     {
         $logger = new Logger('test', [$handler = new TestHandler]);
@@ -46,7 +45,7 @@ class ErrorHandlerTest extends \PHPUnit_Framework_TestCase
     {
         return [
             [null, 10, str_repeat(' ', 1024 * 10), null],
-            [E_ALL, 15, str_repeat(' ', 1024 * 15), E_ALL]
+            [E_ALL, 15, str_repeat(' ', 1024 * 15), E_ALL],
         ];
     }
 
diff --git a/tests/Monolog/Handler/NoopHandlerTest.php b/tests/Monolog/Handler/NoopHandlerTest.php
index df12f4e2..768f5e30 100644
--- a/tests/Monolog/Handler/NoopHandlerTest.php
+++ b/tests/Monolog/Handler/NoopHandlerTest.php
@@ -3,7 +3,7 @@
 /*
  * This file is part of the Monolog package.
  *
- * (c) Roel Harbers <roelharbers@gmail.com>
+ * (c) Jordi Boggiano <j.boggiano@seld.be>
  *
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
diff --git a/tests/Monolog/Handler/RollbarHandlerTest.php b/tests/Monolog/Handler/RollbarHandlerTest.php
index a2465f56..89fc9cb9 100644
--- a/tests/Monolog/Handler/RollbarHandlerTest.php
+++ b/tests/Monolog/Handler/RollbarHandlerTest.php
@@ -76,7 +76,7 @@ class RollbarHandlerTest extends TestCase
     private function createExceptionRecord($level = Logger::DEBUG, $message = 'test', $exception = null): array
     {
         return $this->getRecord($level, $message, [
-            'exception' => $exception ?: new Exception()
+            'exception' => $exception ?: new Exception(),
         ]);
     }
 }
diff --git a/tests/Monolog/Handler/Slack/SlackRecordTest.php b/tests/Monolog/Handler/Slack/SlackRecordTest.php
index e23c793c..e5c44d49 100644
--- a/tests/Monolog/Handler/Slack/SlackRecordTest.php
+++ b/tests/Monolog/Handler/Slack/SlackRecordTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.
@@ -42,8 +42,8 @@ class SlackRecordTest extends TestCase
 
     /**
      * @dataProvider dataGetAttachmentColor
-     * @param  int $logLevel
-     * @param  string $expectedColour RGB hex color or name of Slack color
+     * @param int    $logLevel
+     * @param string $expectedColour RGB hex color or name of Slack color
      * @covers ::getAttachmentColor
      */
     public function testGetAttachmentColor($logLevel, $expectedColour)
@@ -88,7 +88,7 @@ class SlackRecordTest extends TestCase
             array(array(), '[]'),
             array($multipleDimensions, json_encode($multipleDimensions, $jsonPrettyPrintFlag)),
             array($numericKeys, json_encode($numericKeys, $jsonPrettyPrintFlag)),
-            array($singleDimension, json_encode($singleDimension))
+            array($singleDimension, json_encode($singleDimension)),
         );
     }
 
@@ -176,13 +176,17 @@ class SlackRecordTest extends TestCase
         $formatter
             ->expects($this->any())
             ->method('format')
-            ->will($this->returnCallback(function ($record) { return $record['message'] . 'test'; }));
+            ->will($this->returnCallback(function ($record) {
+                return $record['message'] . 'test';
+            }));
 
         $formatter2 = $this->getMock('Monolog\\Formatter\\FormatterInterface');
         $formatter2
             ->expects($this->any())
             ->method('format')
-            ->will($this->returnCallback(function ($record) { return $record['message'] . 'test1'; }));
+            ->will($this->returnCallback(function ($record) {
+                return $record['message'] . 'test1';
+            }));
 
         $message = 'Test message';
         $record = new SlackRecord(null, null, false, null, false, false, array(), $formatter);
@@ -268,13 +272,13 @@ class SlackRecordTest extends TestCase
                 array(
                     'title' => 'Extra',
                     'value' => sprintf('```%s```', json_encode($extra, $this->jsonPrettyPrintFlag)),
-                    'short' => false
+                    'short' => false,
                 ),
                 array(
                     'title' => 'Context',
                     'value' => sprintf('```%s```', json_encode($context, $this->jsonPrettyPrintFlag)),
-                    'short' => false
-                )
+                    'short' => false,
+                ),
             ),
             $attachment['fields']
         );
@@ -296,7 +300,7 @@ class SlackRecordTest extends TestCase
             array(array(
                 'title' => 'Level',
                 'value' => $levelName,
-                'short' => false
+                'short' => false,
             )),
             $attachment['fields']
         );
@@ -322,13 +326,13 @@ class SlackRecordTest extends TestCase
             array(
                 'title' => 'tags',
                 'value' => sprintf('```%s```', json_encode($extra['tags'])),
-                'short' => false
+                'short' => false,
             ),
             array(
                 'title' => 'test',
                 'value' => $context['test'],
-                'short' => false
-            )
+                'short' => false,
+            ),
         );
 
         $attachment = $data['attachments'][0];
@@ -370,12 +374,12 @@ class SlackRecordTest extends TestCase
             array(
                 'title' => 'info',
                 'value' => sprintf('```%s```', json_encode(array('author' => 'Jordi'), $this->jsonPrettyPrintFlag)),
-                'short' => false
+                'short' => false,
             ),
             array(
                 'title' => 'tags',
                 'value' => sprintf('```%s```', json_encode(array('web'))),
-                'short' => false
+                'short' => false,
             ),
         );
 
diff --git a/tests/Monolog/Handler/SlackWebhookHandlerTest.php b/tests/Monolog/Handler/SlackWebhookHandlerTest.php
index 723ae7a5..8ce72108 100644
--- a/tests/Monolog/Handler/SlackWebhookHandlerTest.php
+++ b/tests/Monolog/Handler/SlackWebhookHandlerTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.
diff --git a/tests/Monolog/Handler/SlackbotHandlerTest.php b/tests/Monolog/Handler/SlackbotHandlerTest.php
index a5227120..340c4c65 100644
--- a/tests/Monolog/Handler/SlackbotHandlerTest.php
+++ b/tests/Monolog/Handler/SlackbotHandlerTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.
diff --git a/tests/Monolog/Processor/MercurialProcessorTest.php b/tests/Monolog/Processor/MercurialProcessorTest.php
index 73901b5f..9028e41e 100644
--- a/tests/Monolog/Processor/MercurialProcessorTest.php
+++ b/tests/Monolog/Processor/MercurialProcessorTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php declare(strict_types=1);
 
 /*
  * This file is part of the Monolog package.