diff --git a/src/widgets/kernel/qwidget_p.h b/src/widgets/kernel/qwidget_p.h
index 7eb8d048b3d..a5c7aa5815d 100644
--- a/src/widgets/kernel/qwidget_p.h
+++ b/src/widgets/kernel/qwidget_p.h
@@ -68,7 +68,6 @@ QT_BEGIN_NAMESPACE
 // Extra QWidget data
 //  - to minimize memory usage for members that are seldom used.
 //  - top-level widgets have extra extra data to reduce cost further
-class QWidgetWindow;
 class QPaintEngine;
 class QPixmap;
 class QWidgetBackingStore;
@@ -154,7 +153,7 @@ struct QTLWExtra {
     QWidgetBackingStoreTracker backingStoreTracker;
     QBackingStore *backingStore;
     QPainter *sharedPainter;
-    QWidgetWindow *window;
+    QWindow *window;
     QOpenGLContext *shareContext;
 
     // Implicit pointers (shared_null).