diff --git a/Services/ReadData/External/ReadOrdersService.php b/Services/ReadData/External/ReadOrdersService.php
index ed996eb..46d0236 100644
--- a/Services/ReadData/External/ReadOrdersService.php
+++ b/Services/ReadData/External/ReadOrdersService.php
@@ -85,7 +85,7 @@ public function transform(array $data) {
 
                     $orderPosition->setName($position["ItemTitle"]);
 
-                    if(array_key_exists('ShopProductDetails', $position)) {
+                    if(array_key_exists('ShopProductDetails', $position) && array_key_exists('ProductID', $position['ShopProductDetails'])) {
                         $orderPosition->setExternalIdentifier($position["ShopProductDetails"]["ProductID"]);
                         $orderPosition->setInternalIdentifier($position['ShopProductDetails']['EAN']);
                     } else {