diff --git a/layout/xul/base/src/nsMenuFrame.cpp b/layout/xul/base/src/nsMenuFrame.cpp
index 6db50396c44..62c5bc81cae 100644
--- a/layout/xul/base/src/nsMenuFrame.cpp
+++ b/layout/xul/base/src/nsMenuFrame.cpp
@@ -38,7 +38,7 @@
 // Wrapper for creating a new menu popup container
 //
 nsresult
-NS_NewMenuFrame(nsIFrame** aNewFrame, PRInt32 aFlags)
+NS_NewMenuFrame(nsIFrame** aNewFrame, PRUint32 aFlags)
 {
   NS_PRECONDITION(aNewFrame, "null OUT ptr");
   if (nsnull == aNewFrame) {
diff --git a/layout/xul/base/src/nsMenuFrame.h b/layout/xul/base/src/nsMenuFrame.h
index e4f95004698..855f7f66849 100644
--- a/layout/xul/base/src/nsMenuFrame.h
+++ b/layout/xul/base/src/nsMenuFrame.h
@@ -31,7 +31,7 @@
 #include "nsFrameList.h"
 #include "nsIMenuParent.h"
 
-nsresult NS_NewMenuFrame(nsIFrame** aResult, PRInt32 aFlags) ;
+nsresult NS_NewMenuFrame(nsIFrame** aResult, PRUint32 aFlags) ;
 
 class nsMenuBarFrame;
 class nsMenuPopupFrame;