diff --git a/content/svg/content/src/DOMSVGStringList.cpp b/content/svg/content/src/DOMSVGStringList.cpp
index 7e7614d5b68..3c743c5dfd6 100644
--- a/content/svg/content/src/DOMSVGStringList.cpp
+++ b/content/svg/content/src/DOMSVGStringList.cpp
@@ -99,6 +99,12 @@ DOMSVGStringList::GetNumberOfItems(PRUint32 *aNumberOfItems)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+DOMSVGStringList::GetLength(PRUint32 *aLength)
+{
+  return GetNumberOfItems(aLength);
+}
+
 NS_IMETHODIMP
 DOMSVGStringList::Clear()
 {
diff --git a/content/svg/content/test/test_SVGxxxListIndexing.xhtml b/content/svg/content/test/test_SVGxxxListIndexing.xhtml
index bd29382f719..b0448257c91 100644
--- a/content/svg/content/test/test_SVGxxxListIndexing.xhtml
+++ b/content/svg/content/test/test_SVGxxxListIndexing.xhtml
@@ -13,7 +13,8 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=631437
   <text id="text" x="10 20 30" rotate="40 50 60">abcde</text>
   <path id="path" d="M0,0 L100,100"/>
   <polygon id="poly" points="50,50 70,70 90,50"/>
-  <g id="g" transform="translate(20 30) rotate(50 60 70) scale(2)"/>
+  <g id="g" transform="translate(20 30) rotate(50 60 70) scale(2)"
+     requiredFeatures="foo bar baz"/>
 </svg>
 <script type="text/javascript;version=1.8"><![CDATA[
 var text = document.getElementById("text"),
@@ -69,6 +70,13 @@ var tests = [
                 { values: "skewX(45)", length: 1 },
                 { values: "translate(1 2) rotate(3) scale(4) skewY(5) skewX(6)",
                   length: 5 } ] }
+  { element: g,
+    attribute: "requiredFeatures",
+    listProperty: "requiredFeatures",
+    type: "SVGStringList",
+    subtests: [ { values: null, length: 3 },
+                { values: "foo", length: 1 },
+                { values: "foo bar baz qux", length: 4 } ] }
 ];
 
 for each (let test in tests) {
diff --git a/dom/interfaces/svg/nsIDOMSVGStringList.idl b/dom/interfaces/svg/nsIDOMSVGStringList.idl
index 5cd44b154c8..e57011e1fad 100644
--- a/dom/interfaces/svg/nsIDOMSVGStringList.idl
+++ b/dom/interfaces/svg/nsIDOMSVGStringList.idl
@@ -41,6 +41,7 @@
 interface nsIDOMSVGStringList : nsISupports
 { 
   readonly attribute unsigned long numberOfItems;
+  readonly attribute unsigned long length;
 
   void clear();
           // raises(nsIDOMDOMException);