diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index fb47e62d11..cd3f935c5b 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -98,7 +98,7 @@ void QBackingStore::flush(const QRegion &region, QWindow *win, const QPoint &off
     if (!win)
         win = window();
 
-    if (win && !qt_window_private(win)->receivedExpose) {
+    if (win && win->isTopLevel() && !qt_window_private(win)->receivedExpose) {
         qWarning().nospace() << "QBackingStore::flush() called with non-exposed window "
             << win << ", behavior is undefined";
     }