diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index c8f6dd0..e236acc 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -388,14 +388,16 @@ void QCocoaIntegration::updateScreens()
         }
         siblings << screen;
     }
+    // All screens in mScreens are siblings because we ignored the mirrors.
+    // Update virtual siblings also for screens that are going to be deleted so that we are
+    // not using stale pointers when updating screens of windows.
+    foreach (QCocoaScreen* screen, mScreens)
+        screen->setVirtualSiblings(siblings);
     // Now the leftovers in remainingScreens are no longer current, so we can delete them.
     foreach (QCocoaScreen* screen, remainingScreens) {
         mScreens.removeOne(screen);
         destroyScreen(screen);
     }
-    // All screens in mScreens are siblings, because we ignored the mirrors.
-    foreach (QCocoaScreen* screen, mScreens)
-        screen->setVirtualSiblings(siblings);
 }
 
 QCocoaScreen *QCocoaIntegration::screenAtIndex(int index)