diff --git a/classes/Parser.php b/classes/Parser.php
index a74242f..79d2458 100644
--- a/classes/Parser.php
+++ b/classes/Parser.php
@@ -67,7 +67,7 @@ class Parser {
         $xmlItems = $xml->items->item;
         foreach($xmlItems as $xmlItem) {
             $items[] = array(
-                'productId' => (string)$xmlItem['id'],
+                'productId' => (string)$xmlItem->external_id,
                 'productName' => (string)$xmlItem->name,
                 'quantity' => (string)$xmlItem->quantity,
                 'initialPrice' => (string)$xmlItem->price