diff --git a/mozilla/widget/public/Makefile.in b/mozilla/widget/public/Makefile.in
index d6ce3b2bb4c..687a05c3cbc 100644
--- a/mozilla/widget/public/Makefile.in
+++ b/mozilla/widget/public/Makefile.in
@@ -78,7 +78,7 @@ XPIDLSRCS	= \
 		nsIBidiKeyboard.idl \
 		nsIXRemoteClient.idl \
 		nsIFullScreen.idl \
-		nsNativeScrollbar.idl \
+		nsINativeScrollbar.idl \
 		$(NULL)
 
 ifneq (,$(filter mac cocoa,$(MOZ_WIDGET_TOOLKIT)))
diff --git a/mozilla/widget/public/makefile.win b/mozilla/widget/public/makefile.win
index 720eae4ad9e..52c75a207d3 100644
--- a/mozilla/widget/public/makefile.win
+++ b/mozilla/widget/public/makefile.win
@@ -45,7 +45,7 @@ XPIDLSRCS =               \
   .\nsIBaseWindow.idl \
   .\nsIBidiKeyboard.idl \
   .\nsIFullScreen.idl \
-  .\nsNativeScrollbar.idl \
+  .\nsINativeScrollbar.idl \
   $(NULL)
 
 EXPORTS=\