diff --git a/src/DependencyInjection/BrefMessengerExtension.php b/src/DependencyInjection/BrefMessengerExtension.php
index 6698c56..728a31d 100644
--- a/src/DependencyInjection/BrefMessengerExtension.php
+++ b/src/DependencyInjection/BrefMessengerExtension.php
@@ -28,13 +28,16 @@ public function prepend(ContainerBuilder $container): void
 
     private function getMessengerTransports(array $frameworkConfig): array
     {
-        $transportConfigs = array_column($frameworkConfig, 'messenger.transports');
+        $transportConfigs = array_column(
+            array_column($frameworkConfig, 'messenger'),
+            'transports',
+        );
         $transportConfigs = array_filter($transportConfigs);
 
         if (empty($transportConfigs)) {
             return [];
         }
 
-        return array_merge_recursive(...$transportConfigs);
+        return array_merge(...$transportConfigs);
     }
 }
diff --git a/tests/Unit/DependencyInjection/BrefMessengerExtensionTest.php b/tests/Unit/DependencyInjection/BrefMessengerExtensionTest.php
index e7902a8..db8bade 100644
--- a/tests/Unit/DependencyInjection/BrefMessengerExtensionTest.php
+++ b/tests/Unit/DependencyInjection/BrefMessengerExtensionTest.php
@@ -33,7 +33,7 @@ public function testPrependSetsMessengerTransportsParameter(
             ->with('framework')
             ->willReturn($existConfig);
 
-        $container->expects(self::atMost(2))
+        $container->expects(self::once())
             ->method('setParameter')
             ->with(
                 'messenger.transports',