diff --git a/Command/CacheWarmupCommand.php b/Command/CacheWarmupCommand.php
index 36c2f76e7..5e7dc36f2 100644
--- a/Command/CacheWarmupCommand.php
+++ b/Command/CacheWarmupCommand.php
@@ -53,11 +53,6 @@ protected function configure()
 
 Before running this command, the cache must be empty.
 
-This command does not generate the classes cache (as when executing this
-command, too many classes that should be part of the cache are already loaded
-in memory). Use <comment>curl</comment> or any other similar tool to warm up
-the classes cache if you want.
-
 EOF
             )
         ;
diff --git a/DependencyInjection/FrameworkExtension.php b/DependencyInjection/FrameworkExtension.php
index 2313aea5d..1335e0a80 100644
--- a/DependencyInjection/FrameworkExtension.php
+++ b/DependencyInjection/FrameworkExtension.php
@@ -113,6 +113,7 @@
 use Symfony\Component\Messenger\MessageBus;
 use Symfony\Component\Messenger\MessageBusInterface;
 use Symfony\Component\Messenger\Middleware\RouterContextMiddleware;
+use Symfony\Component\Messenger\Stamp\SerializedMessageStamp;
 use Symfony\Component\Messenger\Transport\Serialization\SerializerInterface;
 use Symfony\Component\Messenger\Transport\TransportFactoryInterface;
 use Symfony\Component\Messenger\Transport\TransportInterface;
@@ -167,8 +168,10 @@
 use Symfony\Component\Notifier\Bridge\Vonage\VonageTransportFactory;
 use Symfony\Component\Notifier\Bridge\Yunpian\YunpianTransportFactory;
 use Symfony\Component\Notifier\Bridge\Zulip\ZulipTransportFactory;
+use Symfony\Component\Notifier\ChatterInterface;
 use Symfony\Component\Notifier\Notifier;
 use Symfony\Component\Notifier\Recipient\Recipient;
+use Symfony\Component\Notifier\TexterInterface;
 use Symfony\Component\Notifier\Transport\TransportFactoryInterface as NotifierTransportFactoryInterface;
 use Symfony\Component\PropertyAccess\PropertyAccessor;
 use Symfony\Component\PropertyInfo\Extractor\PhpDocExtractor;
@@ -649,18 +652,30 @@ public function load(array $configs, ContainerBuilder $container)
         $container->registerAttributeForAutoconfiguration(AsController::class, static function (ChildDefinition $definition, AsController $attribute): void {
             $definition->addTag('controller.service_arguments');
         });
-        $container->registerAttributeForAutoconfiguration(AsMessageHandler::class, static function (ChildDefinition $definition, AsMessageHandler $attribute, \ReflectionClass|\ReflectionMethod $reflector): void {
-            $tagAttributes = get_object_vars($attribute);
-            $tagAttributes['from_transport'] = $tagAttributes['fromTransport'];
-            unset($tagAttributes['fromTransport']);
-            if ($reflector instanceof \ReflectionMethod) {
-                if (isset($tagAttributes['method'])) {
-                    throw new LogicException(sprintf('AsMessageHandler attribute cannot declare a method on "%s::%s()".', $reflector->class, $reflector->name));
+
+        if (class_exists(SerializedMessageStamp::class)) {
+            // symfony/messenger >= 6.1
+            $container->registerAttributeForAutoconfiguration(AsMessageHandler::class, static function (ChildDefinition $definition, AsMessageHandler $attribute, \ReflectionClass|\ReflectionMethod $reflector): void {
+                $tagAttributes = get_object_vars($attribute);
+                $tagAttributes['from_transport'] = $tagAttributes['fromTransport'];
+                unset($tagAttributes['fromTransport']);
+                if ($reflector instanceof \ReflectionMethod) {
+                    if (isset($tagAttributes['method'])) {
+                        throw new LogicException(sprintf('AsMessageHandler attribute cannot declare a method on "%s::%s()".', $reflector->class, $reflector->name));
+                    }
+                    $tagAttributes['method'] = $reflector->getName();
                 }
-                $tagAttributes['method'] = $reflector->getName();
-            }
-            $definition->addTag('messenger.message_handler', $tagAttributes);
-        });
+                $definition->addTag('messenger.message_handler', $tagAttributes);
+            });
+        } else {
+            // symfony/messenger < 6.1
+            $container->registerAttributeForAutoconfiguration(AsMessageHandler::class, static function (ChildDefinition $definition, AsMessageHandler $attribute): void {
+                $tagAttributes = get_object_vars($attribute);
+                $tagAttributes['from_transport'] = $tagAttributes['fromTransport'];
+                unset($tagAttributes['fromTransport']);
+                $definition->addTag('messenger.message_handler', $tagAttributes);
+            });
+        }
 
         if (!$container->getParameter('kernel.debug')) {
             // remove tagged iterator argument for resource checkers
@@ -2482,11 +2497,13 @@ private function registerNotifierConfiguration(array $config, ContainerBuilder $
             $container->getDefinition('chatter.transports')->setArgument(0, $config['chatter_transports']);
         } else {
             $container->removeDefinition('chatter');
+            $container->removeAlias(ChatterInterface::class);
         }
         if ($config['texter_transports']) {
             $container->getDefinition('texter.transports')->setArgument(0, $config['texter_transports']);
         } else {
             $container->removeDefinition('texter');
+            $container->removeAlias(TexterInterface::class);
         }
 
         if ($this->mailerConfigEnabled) {
diff --git a/Test/KernelTestCase.php b/Test/KernelTestCase.php
index 165797504..d189b88db 100644
--- a/Test/KernelTestCase.php
+++ b/Test/KernelTestCase.php
@@ -70,7 +70,7 @@ protected static function bootKernel(array $options = []): KernelInterface
 
         $kernel = static::createKernel($options);
         $kernel->boot();
-        self::$kernel = $kernel;
+        static::$kernel = $kernel;
         static::$booted = true;
 
         return static::$kernel;
diff --git a/Tests/DependencyInjection/FrameworkExtensionTest.php b/Tests/DependencyInjection/FrameworkExtensionTest.php
index a00b5b47b..9a480af2a 100644
--- a/Tests/DependencyInjection/FrameworkExtensionTest.php
+++ b/Tests/DependencyInjection/FrameworkExtensionTest.php
@@ -56,6 +56,8 @@
 use Symfony\Component\HttpKernel\DependencyInjection\LoggerPass;
 use Symfony\Component\HttpKernel\Fragment\FragmentUriGeneratorInterface;
 use Symfony\Component\Messenger\Transport\TransportFactory;
+use Symfony\Component\Notifier\ChatterInterface;
+use Symfony\Component\Notifier\TexterInterface;
 use Symfony\Component\PropertyAccess\PropertyAccessor;
 use Symfony\Component\Security\Core\Security;
 use Symfony\Component\Serializer\Mapping\Loader\AnnotationLoader;
@@ -2018,7 +2020,9 @@ public function testNotifierWithoutTransports()
 
         $this->assertTrue($container->hasDefinition('notifier'));
         $this->assertFalse($container->hasDefinition('chatter'));
+        $this->assertFalse($container->hasAlias(ChatterInterface::class));
         $this->assertFalse($container->hasDefinition('texter'));
+        $this->assertFalse($container->hasAlias(TexterInterface::class));
     }
 
     public function testIfNotifierTransportsAreKnownByFrameworkExtension()
diff --git a/composer.json b/composer.json
index 1a301287d..dc1e717e2 100644
--- a/composer.json
+++ b/composer.json
@@ -48,7 +48,7 @@
         "symfony/http-client": "^5.4|^6.0",
         "symfony/lock": "^5.4|^6.0",
         "symfony/mailer": "^5.4|^6.0",
-        "symfony/messenger": "^6.1",
+        "symfony/messenger": "^5.4|^6.0",
         "symfony/mime": "^5.4|^6.0",
         "symfony/notifier": "^5.4|^6.0",
         "symfony/process": "^5.4|^6.0",

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