diff --git a/src/gui/kernel/qplatformwindow.h b/src/gui/kernel/qplatformwindow.h
index cd621b76364..1c5946dd3cd 100644
--- a/src/gui/kernel/qplatformwindow.h
+++ b/src/gui/kernel/qplatformwindow.h
@@ -60,6 +60,7 @@
 
 QT_BEGIN_NAMESPACE
 
+#define QWINDOWSIZE_MAX ((1<<24)-1)
 
 class QPlatformScreen;
 class QPlatformWindowPrivate;
diff --git a/src/gui/kernel/qwindow_p.h b/src/gui/kernel/qwindow_p.h
index 82d4bd430ce..fef8b4ca727 100644
--- a/src/gui/kernel/qwindow_p.h
+++ b/src/gui/kernel/qwindow_p.h
@@ -62,8 +62,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#define QWINDOWSIZE_MAX ((1<<24)-1)
-
 class Q_GUI_EXPORT QWindowPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QWindow)