diff --git a/dom/events/EventDispatcher.cpp b/dom/events/EventDispatcher.cpp
index 89e5a93ba918..bbbb82799c9c 100644
--- a/dom/events/EventDispatcher.cpp
+++ b/dom/events/EventDispatcher.cpp
@@ -689,7 +689,7 @@ EventDispatcher::CreateEvent(EventTarget* aOwner,
       return NS_NewDOMMutationEvent(aDOMEvent, aOwner, aPresContext,
                                     aEvent->AsMutationEvent());
     case eGUIEventClass:
-    case NS_SCROLLPORT_EVENT:
+    case eScrollPortEventClass:
     case eUIEventClass:
       return NS_NewDOMUIEvent(aDOMEvent, aOwner, aPresContext,
                               aEvent->AsGUIEvent());
diff --git a/dom/events/UIEvent.cpp b/dom/events/UIEvent.cpp
index 3dc9c61479dd..3ea084d21d86 100644
--- a/dom/events/UIEvent.cpp
+++ b/dom/events/UIEvent.cpp
@@ -53,7 +53,7 @@ UIEvent::UIEvent(EventTarget* aOwner,
       break;
     }
 
-    case NS_SCROLLPORT_EVENT:
+    case eScrollPortEventClass:
     {
       InternalScrollPortEvent* scrollEvent = mEvent->AsScrollPortEvent();
       mDetail = (int32_t)scrollEvent->orient;
diff --git a/widget/BasicEvents.h b/widget/BasicEvents.h
index b49496ea9b88..cc20992180a6 100644
--- a/widget/BasicEvents.h
+++ b/widget/BasicEvents.h
@@ -52,7 +52,7 @@ enum EventClassID MOZ_ENUM_TYPE(EventClassIDType)
   eTouchEventClass,                  // WidgetTouchEvent
 
   // ContentEvents.h
-  NS_SCROLLPORT_EVENT,               // InternalScrollPortEvent
+  eScrollPortEventClass,             // InternalScrollPortEvent
   NS_SCROLLAREA_EVENT,               // InternalScrollAreaEvent
   NS_FORM_EVENT,                     // InternalFormEvent
   NS_FOCUS_EVENT,                    // InternalFocusEvent
diff --git a/widget/ContentEvents.h b/widget/ContentEvents.h
index 58a6555ee657..544e979a660d 100644
--- a/widget/ContentEvents.h
+++ b/widget/ContentEvents.h
@@ -39,15 +39,15 @@ class InternalScrollPortEvent : public WidgetGUIEvent
   };
 
   InternalScrollPortEvent(bool aIsTrusted, uint32_t aMessage,
-                          nsIWidget* aWidget) :
-    WidgetGUIEvent(aIsTrusted, aMessage, aWidget, NS_SCROLLPORT_EVENT),
-    orient(vertical)
+                          nsIWidget* aWidget)
+    : WidgetGUIEvent(aIsTrusted, aMessage, aWidget, eScrollPortEventClass)
+    , orient(vertical)
   {
   }
 
   virtual WidgetEvent* Duplicate() const MOZ_OVERRIDE
   {
-    MOZ_ASSERT(mClass == NS_SCROLLPORT_EVENT,
+    MOZ_ASSERT(mClass == eScrollPortEventClass,
                "Duplicate() must be overridden by sub class");
     // Not copying widget, it is a weak reference.
     InternalScrollPortEvent* result =