diff --git a/app/code/core/Mage/Sales/Model/Order/Invoice/Api.php b/app/code/core/Mage/Sales/Model/Order/Invoice/Api.php
index ec70a957bcc..3ed6bfe2752 100644
--- a/app/code/core/Mage/Sales/Model/Order/Invoice/Api.php
+++ b/app/code/core/Mage/Sales/Model/Order/Invoice/Api.php
@@ -121,7 +121,7 @@ public function info($invoiceIncrementId)
      * @param bool $includeComment
      * @return string
      */
-    public function create($orderIncrementId, $itemsQty, $comment = null, $email = false, $includeComment = false)
+    public function create($orderIncrementId, $itemsQty = [], $comment = null, $email = false, $includeComment = false)
     {
         $order = Mage::getModel('sales/order')->loadByIncrementId($orderIncrementId);
 
diff --git a/app/code/core/Mage/Sales/Model/Order/Invoice/Api/V2.php b/app/code/core/Mage/Sales/Model/Order/Invoice/Api/V2.php
index 13d8d45a5c4..c2ca41fe3fd 100644
--- a/app/code/core/Mage/Sales/Model/Order/Invoice/Api/V2.php
+++ b/app/code/core/Mage/Sales/Model/Order/Invoice/Api/V2.php
@@ -38,7 +38,7 @@ class Mage_Sales_Model_Order_Invoice_Api_V2 extends Mage_Sales_Model_Order_Invoi
      * @param bool $includeComment
      * @return string
      */
-    public function create($invoiceIncrementId, $itemsQty, $comment = null, $email = false, $includeComment = false)
+    public function create($invoiceIncrementId, $itemsQty = [], $comment = null, $email = false, $includeComment = false)
     {
         $order = Mage::getModel('sales/order')->loadByIncrementId($invoiceIncrementId);
         $itemsQty = $this->_prepareItemQtyData($itemsQty);