diff --git a/AppKit/CPToolbar.j b/AppKit/CPToolbar.j
index 21fbd788d..5ad5b16fb 100644
--- a/AppKit/CPToolbar.j
+++ b/AppKit/CPToolbar.j
@@ -230,7 +230,7 @@ var CPToolbarsByIdentifier              = nil,
 - (void)_setWindow:(CPWindow)aWindow
 {
     if (_window)
-        [[CPNotificationCenter defaultCenter] removeObserver:self object:_window];
+        [[CPNotificationCenter defaultCenter] removeObserver:self name:nil object:_window];
 
     _window = aWindow;