diff --git a/src/EventSubscriber/SlackNotifySubscriber.php b/src/EventSubscriber/SlackNotifySubscriber.php
index 5544546..a351cd5 100644
--- a/src/EventSubscriber/SlackNotifySubscriber.php
+++ b/src/EventSubscriber/SlackNotifySubscriber.php
@@ -26,13 +26,13 @@ class SlackNotifySubscriber implements EventSubscriberInterface
     private $warehouseRepository;
 
 
-    public function __construct(string $slackWebhookUrl, ProductRepository $productRepository, StockRepository $stockRepository, WarehouseRepository $warehouseRepository)
+    public function __construct(string $slackWebhookUrl, ProductRepository $productRepository, StockRepository $stockRepository, WarehouseRepository $warehouseRepository, LoggerInterface $logger)
     {
         $this->slackWebhookUrl = $slackWebhookUrl;
         $this->productRepository = $productRepository;
         $this->stockRepository = $stockRepository;
         $this->warehouseRepository = $warehouseRepository;
-
+        $this->logger = $logger;
     }
 
     public static function getSubscribedEvents(): array
@@ -65,6 +65,7 @@ class SlackNotifySubscriber implements EventSubscriberInterface
                     $warehouse = $this->getWarehouseByGtin($item['gtin']);
 
                     if ($warehouse == false) {
+                        $this->logger->error('Warehouse not found for GTIN: ' . $item['gtin']);
                         continue;
                     }
 
@@ -82,9 +83,7 @@ class SlackNotifySubscriber implements EventSubscriberInterface
                     $msg .= ' - ' . $item['han'];
                     $msg .= ' * - ' . $item['menge'] . "* \n";
 
-
                     $slack->from('CDS-Notify')->send($msg);
-
                 }
             }
         }
@@ -92,14 +91,14 @@ class SlackNotifySubscriber implements EventSubscriberInterface
 
     /**
      * @param string $gtin
-     * @return array
+     * @return string|bool
      */
-    private function getWarehouseByGtin(string $gtin)
+    private function getWarehouseByGtin(string $gtin): bool|string
     {
         if ($gtin == null) {
             return false;
         }
-        $warehouse = "";
+        $warehouse = false;
 
         $product = $this->productRepository->findOneBy(['gtin' => $gtin]);
 
@@ -125,4 +124,4 @@ class SlackNotifySubscriber implements EventSubscriberInterface
         return $warehouse;
 
     }
-}
+}
\ No newline at end of file