diff --git a/src/DataService/MagentoProductWrapper.php b/src/DataService/MagentoProductWrapper.php
index 190b8be..6c0efb2 100644
--- a/src/DataService/MagentoProductWrapper.php
+++ b/src/DataService/MagentoProductWrapper.php
@@ -35,7 +35,7 @@ public function __construct(Product $product)
      */
     public function getSku(): string
     {
-        return $this->product->getData('sku');
+        return (string)$this->product->getData('sku');
     }