diff --git a/src/bundle/EventSubscriber/SendMessageSiteAccessSubscriber.php b/src/bundle/EventSubscriber/SendMessageSiteAccessSubscriber.php
index 26d21d1..c904109 100644
--- a/src/bundle/EventSubscriber/SendMessageSiteAccessSubscriber.php
+++ b/src/bundle/EventSubscriber/SendMessageSiteAccessSubscriber.php
@@ -9,6 +9,7 @@
 namespace Ibexa\Bundle\Messenger\EventSubscriber;
 
 use Ibexa\Contracts\Messenger\Stamp\SiteAccessStamp;
+use Ibexa\Core\MVC\Symfony\SiteAccess;
 use Ibexa\Core\MVC\Symfony\SiteAccess\SiteAccessServiceInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\Messenger\Event\SendMessageToTransportsEvent;
@@ -33,7 +34,7 @@ public static function getSubscribedEvents(): array
     public function onSendMessageToTransport(SendMessageToTransportsEvent $event): void
     {
         $siteAccess = $this->siteAccessService->getCurrent();
-        if ($siteAccess === null) {
+        if ($siteAccess === null || $siteAccess->matchingType === SiteAccess::MATCHING_TYPE_UNINITIALIZED) {
             return;
         }
 
diff --git a/tests/bundle/EventSubscriber/SendMessageSiteAccessSubscriberTest.php b/tests/bundle/EventSubscriber/SendMessageSiteAccessSubscriberTest.php
index f90e977..fb2e56b 100644
--- a/tests/bundle/EventSubscriber/SendMessageSiteAccessSubscriberTest.php
+++ b/tests/bundle/EventSubscriber/SendMessageSiteAccessSubscriberTest.php
@@ -74,4 +74,23 @@ public function testOnSendMessageToTransportDoesNothingWhenNoSiteAccess(): void
         self::assertNull($updatedEnvelope->last(SiteAccessStamp::class));
         self::assertSame($envelope, $updatedEnvelope);
     }
+
+    public function testOnSendMessageToTransportDoesNothingWhenSiteAccessIsUninitialized(): void
+    {
+        $siteAccess = new SiteAccess('default', SiteAccess::MATCHING_TYPE_UNINITIALIZED);
+        $envelope = new Envelope(new \stdClass());
+        $event = new SendMessageToTransportsEvent($envelope);
+
+        $this->siteAccessService
+            ->expects(self::once())
+            ->method('getCurrent')
+            ->willReturn($siteAccess);
+
+        $this->subscriber->onSendMessageToTransport($event);
+
+        $updatedEnvelope = $event->getEnvelope();
+
+        self::assertNull($updatedEnvelope->last(SiteAccessStamp::class));
+        self::assertSame($envelope, $updatedEnvelope);
+    }
 }