diff --git a/src/widgets/widgets/qmainwindowlayout.cpp b/src/widgets/widgets/qmainwindowlayout.cpp
index b81b17a64ba..869fc49c021 100644
--- a/src/widgets/widgets/qmainwindowlayout.cpp
+++ b/src/widgets/widgets/qmainwindowlayout.cpp
@@ -732,6 +732,7 @@ void QDockWidgetGroupWindow::destroyIfSingleItemLeft()
     reparentToMainWindow(lastDockWidget);
 
     // the group window could still have placeholder items => clear everything
+    layoutInfo()->deleteAllLayoutItems();
     layoutInfo()->item_list.clear();
 
     destroyOrHideIfEmpty();