diff --git a/.php_cs b/.php_cs
index 366ccd08..fe3c5bff 100644
--- a/.php_cs
+++ b/.php_cs
@@ -13,6 +13,12 @@ $finder = Symfony\CS\Finder::create()
     ->files()
     ->name('*.php')
     ->exclude('Fixtures')
+    // The next 4 files are here for forward compatibility, and are not used by
+    // Monolog itself
+    ->exclude(__DIR__.'src/Monolog/Handler/FormattableHandlerInterface.php')
+    ->exclude(__DIR__.'src/Monolog/Handler/FormattableHandlerTrait.php')
+    ->exclude(__DIR__.'src/Monolog/Handler/ProcessableHandlerInterface.php')
+    ->exclude(__DIR__.'src/Monolog/Handler/ProcessableHandlerTrait.php')
     ->in(__DIR__.'/src')
     ->in(__DIR__.'/tests')
 ;
diff --git a/composer.json b/composer.json
index 3b0c8805..097df878 100644
--- a/composer.json
+++ b/composer.json
@@ -59,7 +59,7 @@
     },
     "scripts": {
         "test": [
-            "parallel-lint . --exclude vendor",
+            "parallel-lint . --exclude vendor --exclude src/Monolog/Handler/FormattableHandlerInterface.php  --exclude src/Monolog/Handler/FormattableHandlerTrait.php --exclude src/Monolog/Handler/ProcessableHandlerInterface.php --exclude src/Monolog/Handler/ProcessableHandlerTrait.php",
             "phpunit"
         ]
     }
diff --git a/src/Monolog/Handler/FormattableHandlerInterface.php b/src/Monolog/Handler/FormattableHandlerInterface.php
new file mode 100644
index 00000000..b6d4c6ac
--- /dev/null
+++ b/src/Monolog/Handler/FormattableHandlerInterface.php
@@ -0,0 +1,38 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (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.
+ */
+
+namespace Monolog\Handler;
+
+use Monolog\Formatter\FormatterInterface;
+
+/**
+ * Interface to describe loggers that have a formatter
+ *
+ * @internal This interface is present in monolog 1.x to ease forward compatibility.
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+interface FormattableHandlerInterface
+{
+    /**
+     * Sets the formatter.
+     *
+     * @param  FormatterInterface $formatter
+     * @return HandlerInterface   self
+     */
+    public function setFormatter(FormatterInterface $formatter): HandlerInterface;
+
+    /**
+     * Gets the formatter.
+     *
+     * @return FormatterInterface
+     */
+    public function getFormatter(): FormatterInterface;
+}
diff --git a/src/Monolog/Handler/FormattableHandlerTrait.php b/src/Monolog/Handler/FormattableHandlerTrait.php
new file mode 100644
index 00000000..5233bf55
--- /dev/null
+++ b/src/Monolog/Handler/FormattableHandlerTrait.php
@@ -0,0 +1,62 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (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.
+ */
+
+namespace Monolog\Handler;
+
+use Monolog\Formatter\FormatterInterface;
+use Monolog\Formatter\LineFormatter;
+
+/**
+ * Helper trait for implementing FormattableInterface
+ *
+ * @internal This interface is present in monolog 1.x to ease forward compatibility.
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+trait FormattableHandlerTrait
+{
+    /**
+     * @var FormatterInterface
+     */
+    protected $formatter;
+
+    /**
+     * {@inheritdoc}
+     * @suppress PhanTypeMismatchReturn
+     */
+    public function setFormatter(FormatterInterface $formatter): HandlerInterface
+    {
+        $this->formatter = $formatter;
+
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getFormatter(): FormatterInterface
+    {
+        if (!$this->formatter) {
+            $this->formatter = $this->getDefaultFormatter();
+        }
+
+        return $this->formatter;
+    }
+
+    /**
+     * Gets the default formatter.
+     *
+     * Overwrite this if the LineFormatter is not a good default for your handler.
+     */
+    protected function getDefaultFormatter(): FormatterInterface
+    {
+        return new LineFormatter();
+    }
+}
diff --git a/src/Monolog/Handler/ProcessableHandlerInterface.php b/src/Monolog/Handler/ProcessableHandlerInterface.php
new file mode 100644
index 00000000..bfa71497
--- /dev/null
+++ b/src/Monolog/Handler/ProcessableHandlerInterface.php
@@ -0,0 +1,39 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (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.
+ */
+
+namespace Monolog\Handler;
+
+use Monolog\Processor\ProcessorInterface;
+
+/**
+ * Interface to describe loggers that have processors
+ *
+ * @internal This interface is present in monolog 1.x to ease forward compatibility.
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+interface ProcessableHandlerInterface
+{
+    /**
+     * Adds a processor in the stack.
+     *
+     * @param  ProcessorInterface|callable $callback
+     * @return HandlerInterface            self
+     */
+    public function pushProcessor(callable $callback): HandlerInterface;
+
+    /**
+     * Removes the processor on top of the stack and returns it.
+     *
+     * @throws \LogicException In case the processor stack is empty
+     * @return callable
+     */
+    public function popProcessor(): callable;
+}
diff --git a/src/Monolog/Handler/ProcessableHandlerTrait.php b/src/Monolog/Handler/ProcessableHandlerTrait.php
new file mode 100644
index 00000000..a5092929
--- /dev/null
+++ b/src/Monolog/Handler/ProcessableHandlerTrait.php
@@ -0,0 +1,72 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (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.
+ */
+
+namespace Monolog\Handler;
+
+use Monolog\ResettableInterface;
+
+/**
+ * Helper trait for implementing ProcessableInterface
+ *
+ * @internal This interface is present in monolog 1.x to ease forward compatibility.
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+trait ProcessableHandlerTrait
+{
+    /**
+     * @var callable[]
+     */
+    protected $processors = [];
+
+    /**
+     * {@inheritdoc}
+     * @suppress PhanTypeMismatchReturn
+     */
+    public function pushProcessor(callable $callback): HandlerInterface
+    {
+        array_unshift($this->processors, $callback);
+
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function popProcessor(): callable
+    {
+        if (!$this->processors) {
+            throw new \LogicException('You tried to pop from an empty processor stack.');
+        }
+
+        return array_shift($this->processors);
+    }
+
+    /**
+     * Processes a record.
+     */
+    protected function processRecord(array $record): array
+    {
+        foreach ($this->processors as $processor) {
+            $record = $processor($record);
+        }
+
+        return $record;
+    }
+
+    protected function resetProcessors(): void
+    {
+        foreach ($this->processors as $processor) {
+            if ($processor instanceof ResettableInterface) {
+                $processor->reset();
+            }
+        }
+    }
+}