diff --git a/Tests/Transport/PostmarkTransportFactoryTest.php b/Tests/Transport/PostmarkTransportFactoryTest.php
index ccbd1f1..33a6b66 100644
--- a/Tests/Transport/PostmarkTransportFactoryTest.php
+++ b/Tests/Transport/PostmarkTransportFactoryTest.php
@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\Mailer\Bridge\Postmark\Tests\Transport;
 
+use Psr\Log\NullLogger;
+use Symfony\Component\HttpClient\MockHttpClient;
 use Symfony\Component\Mailer\Bridge\Postmark\Transport\PostmarkApiTransport;
 use Symfony\Component\Mailer\Bridge\Postmark\Transport\PostmarkSmtpTransport;
 use Symfony\Component\Mailer\Bridge\Postmark\Transport\PostmarkTransportFactory;
@@ -20,9 +22,9 @@
 
 class PostmarkTransportFactoryTest extends TransportFactoryTestCase
 {
-    public static function getFactory(): TransportFactoryInterface
+    public function getFactory(): TransportFactoryInterface
     {
-        return new PostmarkTransportFactory(self::getDispatcher(), self::getClient(), self::getLogger());
+        return new PostmarkTransportFactory(null, new MockHttpClient(), new NullLogger());
     }
 
     public static function supportsProvider(): iterable
@@ -55,42 +57,41 @@ public static function supportsProvider(): iterable
 
     public static function createProvider(): iterable
     {
-        $dispatcher = self::getDispatcher();
-        $logger = self::getLogger();
+        $logger = new NullLogger();
 
         yield [
             new Dsn('postmark+api', 'default', self::USER),
-            new PostmarkApiTransport(self::USER, self::getClient(), $dispatcher, $logger),
+            new PostmarkApiTransport(self::USER, new MockHttpClient(), null, $logger),
         ];
 
         yield [
             new Dsn('postmark+api', 'example.com', self::USER, '', 8080),
-            (new PostmarkApiTransport(self::USER, self::getClient(), $dispatcher, $logger))->setHost('example.com')->setPort(8080),
+            (new PostmarkApiTransport(self::USER, new MockHttpClient(), null, $logger))->setHost('example.com')->setPort(8080),
         ];
 
         yield [
             new Dsn('postmark+api', 'example.com', self::USER, '', 8080, ['message_stream' => 'broadcasts']),
-            (new PostmarkApiTransport(self::USER, self::getClient(), $dispatcher, $logger))->setHost('example.com')->setPort(8080)->setMessageStream('broadcasts'),
+            (new PostmarkApiTransport(self::USER, new MockHttpClient(), null, $logger))->setHost('example.com')->setPort(8080)->setMessageStream('broadcasts'),
         ];
 
         yield [
             new Dsn('postmark', 'default', self::USER),
-            new PostmarkSmtpTransport(self::USER, $dispatcher, $logger),
+            new PostmarkSmtpTransport(self::USER, null, $logger),
         ];
 
         yield [
             new Dsn('postmark+smtp', 'default', self::USER),
-            new PostmarkSmtpTransport(self::USER, $dispatcher, $logger),
+            new PostmarkSmtpTransport(self::USER, null, $logger),
         ];
 
         yield [
             new Dsn('postmark+smtps', 'default', self::USER),
-            new PostmarkSmtpTransport(self::USER, $dispatcher, $logger),
+            new PostmarkSmtpTransport(self::USER, null, $logger),
         ];
 
         yield [
             new Dsn('postmark+smtps', 'default', self::USER, null, null, ['message_stream' => 'broadcasts']),
-            (new PostmarkSmtpTransport(self::USER, $dispatcher, $logger))->setMessageStream('broadcasts'),
+            (new PostmarkSmtpTransport(self::USER, null, $logger))->setMessageStream('broadcasts'),
         ];
     }
 
diff --git a/composer.json b/composer.json
index d0081d2..77ff532 100644
--- a/composer.json
+++ b/composer.json
@@ -17,6 +17,7 @@
     ],
     "require": {
         "php": ">=8.1",
+        "psr/event-dispatcher": "^1",
         "symfony/mailer": "^5.4.21|^6.2.7"
     },
     "require-dev": {