diff --git a/mozilla/layout/html/base/src/nsScrollFrame.cpp b/mozilla/layout/html/base/src/nsScrollFrame.cpp
index 087c48bed4e..6129b8578e2 100644
--- a/mozilla/layout/html/base/src/nsScrollFrame.cpp
+++ b/mozilla/layout/html/base/src/nsScrollFrame.cpp
@@ -50,7 +50,6 @@ static NS_DEFINE_IID(kViewCID, NS_VIEW_CID);
 
 static NS_DEFINE_IID(kIViewIID, NS_IVIEW_IID);
 static NS_DEFINE_IID(kScrollViewIID, NS_ISCROLLABLEVIEW_IID);
-static NS_DEFINE_IID(kAreaFrameIID, NS_IAREAFRAME_IID);
 static NS_DEFINE_IID(kIScrollableFrameIID,             NS_ISCROLLABLE_FRAME_IID);
 
 //----------------------------------------------------------------------