diff --git a/widget/src/mac/nsMenuItem.h b/widget/src/mac/nsMenuItem.h
index 233b8eff5ea..c2cd5bca887 100644
--- a/widget/src/mac/nsMenuItem.h
+++ b/widget/src/mac/nsMenuItem.h
@@ -68,6 +68,7 @@ public:
 
   // nsIMenuListener interface
   nsEventStatus MenuSelected(const nsMenuEvent & aMenuEvent);
+  nsEventStatus MenuDeselected(const nsMenuEvent & aMenuEvent);
   
  
 protected: