Index: qmfcapp.cpp
===================================================================
--- qmfcapp.cpp	(revision 504232)
+++ qmfcapp.cpp	(working copy)
@@ -53,6 +53,7 @@
 #include <QtCore/qeventloop.h>
 #include <QtCore/qabstracteventdispatcher.h>
 #include <QtWidgets/qwidget.h>
+#include "qwinwidget.h"
 
 #ifdef QTWINMIGRATE_WITHMFC
 #include <afxwin.h>
@@ -422,13 +423,20 @@
     }
     HWND toplevel = 0;
     if (widget) {
+        bool isEmbeddedInNativeWindow = true;
         HWND parent = (HWND)widget->winId();
         while(parent) {
             toplevel = parent;
+            if (QWidget* tempWidget = QWidget::find((WId)parent)) {
+                if (!dynamic_cast<QWinWidget*>(tempWidget) && tempWidget->isWindow()) {
+                    isEmbeddedInNativeWindow = false;
+                    break;
+                }
+            }
             parent = GetParent(parent);
         }
         HMENU menu = toplevel ? GetMenu(toplevel) : 0;
-        if (menu && GetFocus() == msg->hwnd) {
+        if (isEmbeddedInNativeWindow && menu && GetFocus() == msg->hwnd) {
             if (msg->message == WM_SYSKEYUP && msg->wParam == VK_MENU) {
                 // activate menubar on Alt-up and move focus away
                 SetFocus(toplevel);