diff --git a/src/Symfony/Component/Mailer/Transport/AbstractTransport.php b/src/Symfony/Component/Mailer/Transport/AbstractTransport.php
index d74e2855ff1a..4252455219cb 100644
--- a/src/Symfony/Component/Mailer/Transport/AbstractTransport.php
+++ b/src/Symfony/Component/Mailer/Transport/AbstractTransport.php
@@ -14,6 +14,7 @@
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\EventDispatcher\LegacyEventDispatcherProxy;
 use Symfony\Component\Mailer\DelayedSmtpEnvelope;
 use Symfony\Component\Mailer\Event\MessageEvent;
 use Symfony\Component\Mailer\Exception\TransportException;
@@ -36,7 +37,7 @@ abstract class AbstractTransport implements TransportInterface
 
     public function __construct(EventDispatcherInterface $dispatcher = null, LoggerInterface $logger = null)
     {
-        $this->dispatcher = $dispatcher;
+        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
         $this->logger = $logger ?: new NullLogger();
     }
 
diff --git a/src/Symfony/Component/Messenger/Middleware/SendMessageMiddleware.php b/src/Symfony/Component/Messenger/Middleware/SendMessageMiddleware.php
index 969a120cbfcd..7d25cd573529 100644
--- a/src/Symfony/Component/Messenger/Middleware/SendMessageMiddleware.php
+++ b/src/Symfony/Component/Messenger/Middleware/SendMessageMiddleware.php
@@ -13,6 +13,7 @@
 
 use Psr\Log\LoggerAwareTrait;
 use Psr\Log\NullLogger;
+use Symfony\Component\EventDispatcher\LegacyEventDispatcherProxy;
 use Symfony\Component\Messenger\Envelope;
 use Symfony\Component\Messenger\Event\SendMessageToTransportsEvent;
 use Symfony\Component\Messenger\Stamp\ReceivedStamp;
@@ -38,7 +39,7 @@ class SendMessageMiddleware implements MiddlewareInterface
     public function __construct(SendersLocatorInterface $sendersLocator, EventDispatcherInterface $eventDispatcher = null)
     {
         $this->sendersLocator = $sendersLocator;
-        $this->eventDispatcher = $eventDispatcher;
+        $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
         $this->logger = new NullLogger();
     }
 
diff --git a/src/Symfony/Component/Messenger/Worker.php b/src/Symfony/Component/Messenger/Worker.php
index f463dde78422..3ce1bd79e585 100644
--- a/src/Symfony/Component/Messenger/Worker.php
+++ b/src/Symfony/Component/Messenger/Worker.php
@@ -13,6 +13,7 @@
 
 use Psr\Log\LoggerInterface;
 use Symfony\Component\Debug\Exception\FlattenException;
+use Symfony\Component\EventDispatcher\LegacyEventDispatcherProxy;
 use Symfony\Component\Messenger\Event\WorkerMessageFailedEvent;
 use Symfony\Component\Messenger\Event\WorkerMessageHandledEvent;
 use Symfony\Component\Messenger\Event\WorkerMessageReceivedEvent;
@@ -51,7 +52,7 @@ public function __construct(array $receivers, MessageBusInterface $bus, array $r
         $this->receivers = $receivers;
         $this->bus = $bus;
         $this->retryStrategies = $retryStrategies;
-        $this->eventDispatcher = $eventDispatcher;
+        $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
         $this->logger = $logger;
     }