diff --git a/content/mathml/content/src/nsMathMLElement.cpp b/content/mathml/content/src/nsMathMLElement.cpp
index 31055bf5275..34f36854fa8 100644
--- a/content/mathml/content/src/nsMathMLElement.cpp
+++ b/content/mathml/content/src/nsMathMLElement.cpp
@@ -56,35 +56,14 @@
 //----------------------------------------------------------------------
 // nsISupports methods:
 
-NS_IMETHODIMP 
-nsMathMLElement::QueryInterface(REFNSIID aIID, void** aInstancePtr)
-{
-  NS_PRECONDITION(aInstancePtr, "null out param");
-
-  nsresult rv = nsMathMLElementBase::QueryInterface(aIID, aInstancePtr);
-
-  if (NS_SUCCEEDED(rv))
-    return rv;
-
-  nsISupports *inst = nsnull;
-
-  if (aIID.Equals(NS_GET_IID(nsIDOMNode))) {
-    inst = static_cast<nsIDOMNode *>(this);
-  } else if (aIID.Equals(NS_GET_IID(nsIDOMElement))) {
-    inst = static_cast<nsIDOMElement *>(this);
-  } else if (aIID.Equals(NS_GET_IID(nsIClassInfo))) {
-    inst = NS_GetDOMClassInfoInstance(eDOMClassInfo_Element_id);
-    NS_ENSURE_TRUE(inst, NS_ERROR_OUT_OF_MEMORY);
-  } else {
-    return PostQueryInterface(aIID, aInstancePtr);
-  }
-
-  NS_ADDREF(inst);
-
-  *aInstancePtr = inst;
-
-  return NS_OK;
-}
+NS_INTERFACE_TABLE_HEAD(nsMathMLElement)
+  NS_NODE_OFFSET_AND_INTERFACE_TABLE_BEGIN(nsMathMLElement)
+    NS_INTERFACE_TABLE_ENTRY(nsMathMLElement, nsIDOMNode)
+    NS_INTERFACE_TABLE_ENTRY(nsMathMLElement, nsIDOMElement)
+  NS_OFFSET_AND_INTERFACE_TABLE_END
+  NS_ELEMENT_INTERFACE_TABLE_TO_MAP_SEGUE
+  NS_INTERFACE_MAP_ENTRY_CONTENT_CLASSINFO(MathMLElement)
+NS_ELEMENT_INTERFACE_MAP_END
 
 NS_IMPL_ADDREF_INHERITED(nsMathMLElement, nsMathMLElementBase)
 NS_IMPL_RELEASE_INHERITED(nsMathMLElement, nsMathMLElementBase)
diff --git a/dom/public/nsDOMClassInfoID.h b/dom/public/nsDOMClassInfoID.h
index 89e37611352..a5258e57d46 100644
--- a/dom/public/nsDOMClassInfoID.h
+++ b/dom/public/nsDOMClassInfoID.h
@@ -454,6 +454,10 @@ enum nsDOMClassInfoID {
 
   eDOMClassInfo_SimpleGestureEvent_id,
 
+#ifdef MOZ_MATHML
+  eDOMClassInfo_MathMLElement_id,
+#endif
+
   // This one better be the last one in this list
   eDOMClassInfoIDCount
 };
diff --git a/dom/src/base/nsDOMClassInfo.cpp b/dom/src/base/nsDOMClassInfo.cpp
index 85f435a6ab2..eac4da28c2f 100644
--- a/dom/src/base/nsDOMClassInfo.cpp
+++ b/dom/src/base/nsDOMClassInfo.cpp
@@ -1299,6 +1299,11 @@ static nsDOMClassInfoData sClassInfoData[] = {
 
   NS_DEFINE_CLASSINFO_DATA(SimpleGestureEvent, nsDOMGenericSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS)
+
+#ifdef MOZ_MATHML
+  NS_DEFINE_CLASSINFO_DATA_WITH_NAME(MathMLElement, Element, nsElementSH,
+                                     ELEMENT_SCRIPTABLE_FLAGS)
+#endif
 };
 
 // Objects that shuld be constructable through |new Name();|
@@ -3542,6 +3547,16 @@ nsDOMClassInfo::Init()
     DOM_CLASSINFO_UI_EVENT_MAP_ENTRIES
   DOM_CLASSINFO_MAP_END
 
+#ifdef MOZ_MATHML
+  DOM_CLASSINFO_MAP_BEGIN_NO_CLASS_IF(MathMLElement, nsIDOMElement)
+    DOM_CLASSINFO_MAP_ENTRY(nsIDOMElement)
+    DOM_CLASSINFO_MAP_ENTRY(nsIDOMNSElement)
+    DOM_CLASSINFO_MAP_ENTRY(nsIDOMEventTarget)
+    DOM_CLASSINFO_MAP_ENTRY(nsIDOM3Node)
+    DOM_CLASSINFO_MAP_ENTRY(nsIDOMNodeSelector)
+  DOM_CLASSINFO_MAP_END
+#endif
+
 #ifdef NS_DEBUG
   {
     PRUint32 i = NS_ARRAY_LENGTH(sClassInfoData);