diff --git a/src/window.h b/src/window.h
index 4c5b640ec5..535a425a6b 100644
--- a/src/window.h
+++ b/src/window.h
@@ -79,8 +79,6 @@ class KWIN_EXPORT Window : public QObject
 {
     Q_OBJECT
 
-    Q_PROPERTY(qulonglong frameId READ frameId)
-
     /**
      * This property holds rectangle that the pixmap or buffer of this Window
      * occupies on the screen. This rectangle includes invisible portions of the
@@ -131,8 +129,6 @@ class KWIN_EXPORT Window : public QObject
      */
     Q_PROPERTY(KWin::Output *output READ output NOTIFY screenChanged)
 
-    Q_PROPERTY(qulonglong windowId READ window CONSTANT)
-
     Q_PROPERTY(QRectF rect READ rect)
     Q_PROPERTY(QPointF clientPos READ clientPos)
     Q_PROPERTY(QSizeF clientSize READ clientSize)
diff --git a/src/x11window.h b/src/x11window.h
index 5bc7ac100b..29b28fba39 100644
--- a/src/x11window.h
+++ b/src/x11window.h
@@ -92,6 +92,8 @@ class KWIN_EXPORT X11Window : public Window
      * Only GTK+ are detected.
      */
     Q_PROPERTY(bool clientSideDecorated READ isClientSideDecorated NOTIFY clientSideDecoratedChanged)
+    Q_PROPERTY(qulonglong frameId READ frameId CONSTANT)
+    Q_PROPERTY(qulonglong windowId READ window CONSTANT)
 public:
     explicit X11Window();
     ~X11Window() override; ///< Use destroyWindow() or releaseWindow()