Index: /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineLogicFullscreen.cpp
===================================================================
--- /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineLogicFullscreen.cpp	(revision 80652)
+++ /trunk/src/VBox/Frontends/VirtualBox/src/runtime/fullscreen/UIMachineLogicFullscreen.cpp	(revision 80653)
@@ -549,21 +549,21 @@
             /* Logic => window signals: */
             connect(this, &UIMachineLogicFullscreen::sigNotifyAboutNativeFullscreenShouldBeEntered,
-                    pMachineWindow, &UIMachineWindow::sltEnterNativeFullscreen);
+                    qobject_cast<UIMachineWindowFullscreen*>(pMachineWindow), &UIMachineWindowFullscreen::sltEnterNativeFullscreen);
             connect(this, &UIMachineLogicFullscreen::sigNotifyAboutNativeFullscreenShouldBeExited,
-                    pMachineWindow, &UIMachineWindow::sltExitNativeFullscreen);
+                    qobject_cast<UIMachineWindowFullscreen*>(pMachineWindow), &UIMachineWindowFullscreen::sltExitNativeFullscreen);
             /* Window => logic signals: */
-            connect(pMachineWindow, &UIMachineWindow::sigNotifyAboutNativeFullscreenWillEnter,
+            connect(qobject_cast<UIMachineWindowFullscreen*>(pMachineWindow), &UIMachineWindowFullscreen::sigNotifyAboutNativeFullscreenWillEnter,
                     this, &UIMachineLogicFullscreen::sltHandleNativeFullscreenWillEnter,
-                    Qt::QueuedConnection);
-            connect(pMachineWindow, &UIMachineWindow::sigNotifyAboutNativeFullscreenDidEnter,
+                     Qt::QueuedConnection);
+            connect(qobject_cast<UIMachineWindowFullscreen*>(pMachineWindow), &UIMachineWindowFullscreen::sigNotifyAboutNativeFullscreenDidEnter,
                     this, &UIMachineLogicFullscreen::sltHandleNativeFullscreenDidEnter,
                     Qt::QueuedConnection);
-            connect(pMachineWindow, &UIMachineWindow::sigNotifyAboutNativeFullscreenWillExit,
+            connect(qobject_cast<UIMachineWindowFullscreen*>(pMachineWindow), &UIMachineWindowFullscreen::sigNotifyAboutNativeFullscreenWillExit,
                     this, &UIMachineLogicFullscreen::sltHandleNativeFullscreenWillExit,
                     Qt::QueuedConnection);
-            connect(pMachineWindow, &UIMachineWindow::sigNotifyAboutNativeFullscreenDidExit,
+            connect(qobject_cast<UIMachineWindowFullscreen*>(pMachineWindow), &UIMachineWindowFullscreen::sigNotifyAboutNativeFullscreenDidExit,
                     this, &UIMachineLogicFullscreen::sltHandleNativeFullscreenDidExit,
                     Qt::QueuedConnection);
-            connect(pMachineWindow, &UIMachineWindow::sigNotifyAboutNativeFullscreenFailToEnter,
+            connect(qobject_cast<UIMachineWindowFullscreen*>(pMachineWindow), &UIMachineWindowFullscreen::sigNotifyAboutNativeFullscreenFailToEnter,
                     this, &UIMachineLogicFullscreen::sltHandleNativeFullscreenFailToEnter,
                     Qt::QueuedConnection);