diff --git a/include/wx/cocoa/mbarman.h b/include/wx/cocoa/mbarman.h
index f21dac7899..52a8c058c7 100644
--- a/include/wx/cocoa/mbarman.h
+++ b/include/wx/cocoa/mbarman.h
@@ -43,7 +43,7 @@ public:
     void SetMainMenuBar(wxMenuBar* menubar);
     void CocoaInternalIdle();
     void WindowDidBecomeKey(wxTopLevelWindowNative *win);
-    void WindowDidResignKey(wxTopLevelWindowNative *win);
+    void WindowDidResignKey(wxTopLevelWindowNative *win, bool uninstallMenuBar = true);
     void WindowDidBecomeMain(wxTopLevelWindowNative *win);
     void WindowDidResignMain(wxTopLevelWindowNative *win);
     void UpdateWindowMenuBar(wxTopLevelWindowNative *win);
diff --git a/src/cocoa/mbarman.mm b/src/cocoa/mbarman.mm
index b2b916054d..ecdd3d3c16 100644
--- a/src/cocoa/mbarman.mm
+++ b/src/cocoa/mbarman.mm
@@ -161,21 +161,22 @@ void wxMenuBarManager::InstallMainMenu()
 
 void wxMenuBarManager::WindowDidBecomeKey(wxTopLevelWindowNative *win)
 {
-//    wxASSERT(!m_windowKey);
+    wxASSERT(!m_windowKey);
     m_windowKey = win;
     InstallMenuBarForWindow(win);
 }
 
-void wxMenuBarManager::WindowDidResignKey(wxTopLevelWindowNative *win)
+void wxMenuBarManager::WindowDidResignKey(wxTopLevelWindowNative *win, bool uninstallMenuBar)
 {
     wxASSERT(m_windowKey==win);
     m_windowKey = NULL;
-    SetMenuBar(NULL);
+    if(uninstallMenuBar)
+        SetMenuBar(NULL);
 }
 
 void wxMenuBarManager::WindowDidBecomeMain(wxTopLevelWindowNative *win)
 {
-//    wxASSERT(!m_windowMain);
+    wxASSERT(!m_windowMain);
     m_windowMain = win;
 }