diff --git a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
index 2dd441182d..098f168e3b 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
+++ b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
@@ -7,6 +7,12 @@ CHANGELOG
  * Not passing the project directory to the constructor of the `AssetsInstallCommand` is deprecated. This argument will
    be mandatory in 5.0.
 
+ * [BC Break] When using Messenger, the default transport changed from
+   using Symfony's serializer service to use `PhpSerializer`, which uses
+   PHP's native `serialize()` and `unserialize()` functions. To use the
+   original serialization method, set the `framework.messenger.serializer.id`
+   config option to `messenger.transport.symfony_serializer`.
+
 4.2.0
 -----
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/messenger.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/messenger.xml
index 9f87bc8f26..d092728399 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/messenger.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/messenger.xml
@@ -24,7 +24,7 @@
         </service>
         <service id="Symfony\Component\Messenger\Transport\Serialization\SerializerInterface" alias="messenger.transport.serializer" />
 
-        <service id="messenger.transport.native_php_serializer"  class="Symfony\Component\Messenger\Transport\Serialization\Serializer" />
+        <service id="messenger.transport.native_php_serializer" class="Symfony\Component\Messenger\Transport\Serialization\Serializer" />
 
         <!-- Middleware -->
         <service id="messenger.middleware.handle_message" class="Symfony\Component\Messenger\Middleware\HandleMessageMiddleware" abstract="true">
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
index 453ccf449d..d8acb04909 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
@@ -19,7 +19,6 @@ use Symfony\Component\Config\Definition\Exception\InvalidConfigurationException;
 use Symfony\Component\Config\Definition\Processor;
 use Symfony\Component\Lock\Store\SemaphoreStore;
 use Symfony\Component\Messenger\MessageBusInterface;
-use Symfony\Component\Serializer\Serializer;
 
 class ConfigurationTest extends TestCase
 {
@@ -295,7 +294,7 @@ class ConfigurationTest extends TestCase
                 'routing' => [],
                 'transports' => [],
                 'serializer' => [
-                    'id' => !class_exists(FullStack::class) && class_exists(Serializer::class) ? 'messenger.transport.symfony_serializer' : null,
+                    'id' => 'messenger.transport.native_php_serializer',
                     'format' => 'json',
                     'context' => [],
                 ],
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
index 862786c9b8..6d3563d078 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
@@ -660,7 +660,7 @@ abstract class FrameworkExtensionTest extends TestCase
 
     /**
      * @expectedException \Symfony\Component\DependencyInjection\Exception\LogicException
-     * @expectedExceptionMessage The default Messenger serializer cannot be enabled as the Serializer support is not available. Try enabling it or running "composer require symfony/serializer-pack".
+     * @expectedExceptionMessage The Messenger serializer cannot be enabled as the Serializer support is not available. Try enabling it or running "composer require symfony/serializer-pack".
      */
     public function testMessengerTransportConfigurationWithoutSerializer()
     {
diff --git a/src/Symfony/Component/Messenger/CHANGELOG.md b/src/Symfony/Component/Messenger/CHANGELOG.md
index eb1268e25e..75a185a13a 100644
--- a/src/Symfony/Component/Messenger/CHANGELOG.md
+++ b/src/Symfony/Component/Messenger/CHANGELOG.md
@@ -1,6 +1,12 @@
 CHANGELOG
 =========
 
+4.3.0
+-----
+
+ * Added `PhpSerializer` which uses PHP's native `serialize()` and
+   `unserialize()` to serialize messages to a transport
+
 4.2.0
 -----
 
diff --git a/src/Symfony/Component/Messenger/Transport/Serialization/PhpSerializer.php b/src/Symfony/Component/Messenger/Transport/Serialization/PhpSerializer.php
index 955b6f5467..ec6176c85d 100644
--- a/src/Symfony/Component/Messenger/Transport/Serialization/PhpSerializer.php
+++ b/src/Symfony/Component/Messenger/Transport/Serialization/PhpSerializer.php
@@ -15,7 +15,7 @@ use Symfony\Component\Messenger\Envelope;
 use Symfony\Component\Messenger\Exception\InvalidArgumentException;
 
 /**
- * @author Ruyan Weaver<ryan@symfonycasts.com>
+ * @author Ryan Weaver<ryan@symfonycasts.com>
  *
  * @experimental in 4.2
  */