diff --git a/src/private/quick/QWidgetAdapter_quick.cpp b/src/private/quick/QWidgetAdapter_quick.cpp
index f23d94bc..d573799c 100644
--- a/src/private/quick/QWidgetAdapter_quick.cpp
+++ b/src/private/quick/QWidgetAdapter_quick.cpp
@@ -159,7 +159,7 @@ WId QWidgetAdapter::winId() const
     if (QWindow *w = windowHandle())
         return w->winId();
 
-    return -1;
+    return WId(-1);
 }
 
 FloatingWindow * QWidgetAdapter::floatingWindow() const