diff --git a/src/Plugin/Router/AsyncSwitchMessageRouter.php b/src/Plugin/Router/AsyncSwitchMessageRouter.php
index 290bc82..d37ec27 100644
--- a/src/Plugin/Router/AsyncSwitchMessageRouter.php
+++ b/src/Plugin/Router/AsyncSwitchMessageRouter.php
@@ -18,6 +18,7 @@
 use Prooph\ServiceBus\Async\MessageProducer;
 use Prooph\ServiceBus\CommandBus;
 use Prooph\ServiceBus\EventBus;
+use Prooph\ServiceBus\Exception\RuntimeException;
 use Prooph\ServiceBus\MessageBus;
 use Prooph\ServiceBus\Plugin\AbstractPlugin;
 use Prooph\ServiceBus\QueryBus;
@@ -71,9 +72,11 @@ public function onRouteMessage(ActionEvent $actionEvent): void
 
             if ($actionEvent->getTarget() instanceof CommandBus || $actionEvent->getTarget() instanceof QueryBus) {
                 $actionEvent->setParam(MessageBus::EVENT_PARAM_MESSAGE_HANDLER, $this->asyncMessageProducer);
-            } else {
+            } elseif ($actionEvent->getTarget() instanceof EventBus) {
                 //Target is an event bus so we set message producer as the only listener of the message
                 $actionEvent->setParam(EventBus::EVENT_PARAM_EVENT_LISTENERS, [$this->asyncMessageProducer]);
+            } else {
+                throw new RuntimeException('Unexpected bus implementation. This plugin is only compatible with standard CommandBus, QueryBus and EventBus implementations.');
             }
 
             return;
diff --git a/tests/Plugin/Router/AsyncSwitchMessageRouterTest.php b/tests/Plugin/Router/AsyncSwitchMessageRouterTest.php
index c66c92a..93fc063 100644
--- a/tests/Plugin/Router/AsyncSwitchMessageRouterTest.php
+++ b/tests/Plugin/Router/AsyncSwitchMessageRouterTest.php
@@ -18,6 +18,7 @@
 use Prooph\ServiceBus\Async\MessageProducer;
 use Prooph\ServiceBus\CommandBus;
 use Prooph\ServiceBus\EventBus;
+use Prooph\ServiceBus\Exception\RuntimeException;
 use Prooph\ServiceBus\MessageBus;
 use Prooph\ServiceBus\Plugin\Router\AsyncSwitchMessageRouter;
 use Prooph\ServiceBus\Plugin\Router\EventRouter;
@@ -196,4 +197,34 @@ public function it_sets_message_producer_as_event_listener_if_target_is_an_event
         $this->assertArrayHasKey('handled-async', $updatedMessage->metadata());
         $this->assertTrue($updatedMessage->metadata()['handled-async']);
     }
+
+    /**
+     * @test
+     */
+    public function it_throws_exception_if_target_is_unknown_bus(): void
+    {
+        $messageProducer = $this->prophesize(MessageProducer::class);
+
+        $message = AsyncEvent::createEvent('test-data');
+
+        $actionEvent = new DefaultActionEvent(
+            MessageBus::EVENT_DISPATCH,
+            $this->prophesize(MessageBus::class),
+            [
+                MessageBus::EVENT_PARAM_MESSAGE_NAME => get_class($message),
+                MessageBus::EVENT_PARAM_MESSAGE => $message,
+            ]
+        );
+
+        $router = new AsyncSwitchMessageRouter(new EventRouter(), $messageProducer->reveal());
+        try {
+            $router->onRouteMessage($actionEvent);
+            $this->fail();
+        } catch (RuntimeException $exception) {
+        }
+
+        $updatedMessage = $actionEvent->getParam(MessageBus::EVENT_PARAM_MESSAGE);
+        $this->assertArrayHasKey('handled-async', $updatedMessage->metadata());
+        $this->assertTrue($updatedMessage->metadata()['handled-async']);
+    }
 }