diff --git a/app/code/core/Mage/Sales/Model/Order/Shipment/Api.php b/app/code/core/Mage/Sales/Model/Order/Shipment/Api.php
index ff5de11a574..9f5b284732c 100644
--- a/app/code/core/Mage/Sales/Model/Order/Shipment/Api.php
+++ b/app/code/core/Mage/Sales/Model/Order/Shipment/Api.php
@@ -173,9 +173,10 @@ public function create(
      * @param string $carrier
      * @param string $title
      * @param string $trackNumber
+     * @param null|float $weight
      * @return int
      */
-    public function addTrack($shipmentIncrementId, $carrier, $title, $trackNumber)
+    public function addTrack($shipmentIncrementId, $carrier, $title, $trackNumber, $weight = null)
     {
         $shipment = Mage::getModel('sales/order_shipment')->loadByIncrementId($shipmentIncrementId);
 
@@ -194,6 +195,10 @@ public function addTrack($shipmentIncrementId, $carrier, $title, $trackNumber)
                     ->setCarrierCode($carrier)
                     ->setTitle($title);
 
+        if (!empty($weight)) {
+            $track->setWeight($weight);
+        }
+
         $shipment->addTrack($track);
 
         try {
diff --git a/app/code/core/Mage/Sales/etc/wsdl.xml b/app/code/core/Mage/Sales/etc/wsdl.xml
index 742d637c77c..fd19f3ea2b0 100644
--- a/app/code/core/Mage/Sales/etc/wsdl.xml
+++ b/app/code/core/Mage/Sales/etc/wsdl.xml
@@ -843,6 +843,7 @@
         <part name="carrier" type="xsd:string" />
         <part name="title" type="xsd:string" />
         <part name="trackNumber" type="xsd:string" />
+        <part name="weight" type="xsd:double" minOccurs="0" />
     </message>
     <message name="salesOrderShipmentAddTrackResponse">
         <part name="result" type="xsd:int" />
diff --git a/app/code/core/Mage/Sales/etc/wsi.xml b/app/code/core/Mage/Sales/etc/wsi.xml
index c237ea0ab81..f13681cf9d8 100644
--- a/app/code/core/Mage/Sales/etc/wsi.xml
+++ b/app/code/core/Mage/Sales/etc/wsi.xml
@@ -881,6 +881,7 @@
                         <xsd:element minOccurs="1" maxOccurs="1" name="carrier" type="xsd:string" />
                         <xsd:element minOccurs="1" maxOccurs="1" name="title" type="xsd:string" />
                         <xsd:element minOccurs="1" maxOccurs="1" name="trackNumber" type="xsd:string" />
+                        <xsd:element minOccurs="0" maxOccurs="1" name="weight" type="xsd:double" />
                     </xsd:sequence>
                 </xsd:complexType>
             </xsd:element>