diff --git a/src/widgets/widgets/qmainwindowlayout.cpp b/src/widgets/widgets/qmainwindowlayout.cpp
index 14a8bbd857d..b345356349d 100644
--- a/src/widgets/widgets/qmainwindowlayout.cpp
+++ b/src/widgets/widgets/qmainwindowlayout.cpp
@@ -728,6 +728,7 @@ void QDockWidgetGroupWindow::destroyIfSingleItemLeft()
     reparentToMainWindow(lastDockWidget);
 
     // the group window could still have placeholder items => clear everything
+    layoutInfo()->deleteAllLayoutItems();
     layoutInfo()->item_list.clear();
 
     // remove the group window and the dock's item_list pointing to it.