diff --git a/src/interfaces/window.cpp b/src/interfaces/window.cpp
index 4f56bfc..5dbd8cc 100644
--- a/src/interfaces/window.cpp
+++ b/src/interfaces/window.cpp
@@ -6,9 +6,6 @@
 
 #include "window.h"
 #include "../qwaylandlayershellintegration_p.h"
-#if QT_VERSION < QT_VERSION_CHECK(6, 6, 0)
-#include "../qwaylandlayersurface_p.h"
-#endif
 
 #include <layershellqt_logging.h>
 
@@ -141,21 +138,6 @@ void Window::setCloseOnDismissed(bool close)
     d->closeOnDismissed = close;
 }
 
-#if QT_VERSION < QT_VERSION_CHECK(6, 6, 0)
-void Window::attachPopup(QWindow *window, xdg_popup *popup)
-{
-    auto waylandWindow = dynamic_cast<QtWaylandClient::QWaylandWindow *>(window->handle());
-    if (!waylandWindow) {
-        return;
-    }
-
-    auto shellSurface = dynamic_cast<QWaylandLayerSurface *>(waylandWindow->shellSurface());
-    if (shellSurface) {
-        shellSurface->get_popup(popup);
-    }
-}
-#endif
-
 Window::Window(QWindow *window)
     : QObject(window)
     , d(new WindowPrivate(window))
diff --git a/src/interfaces/window.h b/src/interfaces/window.h
index 3f3ae80..8a5bf95 100644
--- a/src/interfaces/window.h
+++ b/src/interfaces/window.h
@@ -14,10 +14,6 @@
 
 #include "layershellqt_export.h"
 
-#if QT_VERSION < QT_VERSION_CHECK(6, 6, 0)
-struct xdg_popup;
-#endif
-
 namespace LayerShellQt
 {
 class WindowPrivate;
@@ -120,10 +116,6 @@ public:
      */
     static Window *get(QWindow *window);
 
-#if QT_VERSION < QT_VERSION_CHECK(6, 6, 0)
-    static void attachPopup(QWindow *window, xdg_popup *popup);
-#endif
-
     static Window *qmlAttachedProperties(QObject *object);
 
 Q_SIGNALS: