diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 3e2d8b1b21..83ce1d07ff 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -181,7 +181,6 @@ target_sources(kwin PRIVATE
     xdgshellintegration.cpp
     xdgshellwindow.cpp
     xkb.cpp
-    xwaylandwindow.cpp
 )
 
 target_link_libraries(kwin
diff --git a/src/workspace.cpp b/src/workspace.cpp
index 3c02e13b7f..891000ce94 100644
--- a/src/workspace.cpp
+++ b/src/workspace.cpp
@@ -57,7 +57,6 @@
 #include "virtualdesktops.h"
 #include "was_user_interaction_x11_filter.h"
 #include "wayland_server.h"
-#include "xwaylandwindow.h"
 // KDE
 #include <KConfig>
 #include <KConfigGroup>
@@ -653,12 +652,7 @@ void Workspace::removeFromStack(Window *window)
 X11Window *Workspace::createX11Window(xcb_window_t windowId, bool is_mapped)
 {
     StackingUpdatesBlocker blocker(this);
-    X11Window *window = nullptr;
-    if (kwinApp()->operationMode() == Application::OperationModeX11) {
-        window = new X11Window();
-    } else {
-        window = new XwaylandWindow();
-    }
+    X11Window *window = new X11Window();
     setupWindowConnections(window);
     if (X11Compositor *compositor = X11Compositor::self()) {
         connect(window, &X11Window::blockingCompositingChanged, compositor, &X11Compositor::updateClientCompositeBlocking);
diff --git a/src/x11window.cpp b/src/x11window.cpp
index 0ed0569e22..de8b5fa621 100644
--- a/src/x11window.cpp
+++ b/src/x11window.cpp
@@ -1169,6 +1169,21 @@ bool X11Window::manage(xcb_window_t w, bool isMapped)
         info.setOpacityF(opacity());
     });
 
+    switch (kwinApp()->operationMode()) {
+    case Application::OperationModeXwayland:
+        // The wayland surface is associated with the window asynchronously.
+        if (surface()) {
+            associate();
+        } else {
+            connect(this, &Window::surfaceChanged, this, &X11Window::associate);
+        }
+        break;
+    case Application::OperationModeX11:
+        break;
+    case Application::OperationModeWaylandOnly:
+        Q_UNREACHABLE();
+    }
+
     return true;
 }
 
@@ -2466,7 +2481,16 @@ void X11Window::getIcons()
  */
 bool X11Window::wantsSyncCounter() const
 {
-    return true;
+    if (!waylandServer()) {
+        return true;
+    }
+    // When the frame window is resized, the attached buffer will be destroyed by
+    // Xwayland, causing unexpected invalid previous and current window pixmaps.
+    // With the addition of multiple window buffers in Xwayland 1.21, X11 clients
+    // are no longer able to destroy the buffer after it's been committed and not
+    // released by the compositor yet.
+    static const quint32 xwaylandVersion = xcb_get_setup(kwinApp()->x11Connection())->release_number;
+    return xwaylandVersion >= 12100000;
 }
 
 void X11Window::getSyncCounter()
@@ -4987,12 +5011,18 @@ void X11Window::updateWindowPixmap()
 
 void X11Window::associate()
 {
+    auto handleMapped = [this]() {
+        if (syncRequest().counter == XCB_NONE) { // cannot detect complete redraw, consider done now
+            setReadyForPainting();
+        }
+    };
+
     if (surface()->isMapped()) {
-        setReadyForPainting();
+        handleMapped();
     } else {
         // Queued connection because we want to mark the window ready for painting after
         // the associated surface item has processed the new surface state.
-        connect(surface(), &KWaylandServer::SurfaceInterface::mapped, this, &X11Window::setReadyForPainting, Qt::QueuedConnection);
+        connect(surface(), &KWaylandServer::SurfaceInterface::mapped, this, handleMapped, Qt::QueuedConnection);
     }
 }
 
diff --git a/src/x11window.h b/src/x11window.h
index f6e77e9c62..3bc77ac7c9 100644
--- a/src/x11window.h
+++ b/src/x11window.h
@@ -285,7 +285,7 @@ public:
     {
         return m_syncRequest;
     }
-    virtual bool wantsSyncCounter() const;
+    bool wantsSyncCounter() const;
     void handleSync();
     void handleSyncTimeout();
 
diff --git a/src/xwaylandwindow.cpp b/src/xwaylandwindow.cpp
deleted file mode 100644
index 32fac66ec8..0000000000
--- a/src/xwaylandwindow.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
-    KWin - the KDE window manager
-    This file is part of the KDE project.
-
-    SPDX-FileCopyrightText: 2020 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
-
-    SPDX-License-Identifier: GPL-2.0-or-later
-*/
-
-#include "xwaylandwindow.h"
-#include "wayland/surface_interface.h"
-
-using namespace KWaylandServer;
-
-namespace KWin
-{
-
-XwaylandWindow::XwaylandWindow()
-{
-    // The wayland surface is associated with the Xwayland window asynchronously.
-    connect(this, &Window::surfaceChanged, this, &XwaylandWindow::associate);
-}
-
-void XwaylandWindow::associate()
-{
-    if (surface()->isMapped()) {
-        initialize();
-    } else {
-        // Queued connection because we want to mark the window ready for painting after
-        // the associated surface item has processed the new surface state.
-        connect(surface(), &SurfaceInterface::mapped, this, &XwaylandWindow::initialize, Qt::QueuedConnection);
-    }
-}
-
-void XwaylandWindow::initialize()
-{
-    if (!readyForPainting()) { // avoid "setReadyForPainting()" function calling overhead
-        if (syncRequest().counter == XCB_NONE) { // cannot detect complete redraw, consider done now
-            setReadyForPainting();
-        }
-    }
-}
-
-bool XwaylandWindow::wantsSyncCounter() const
-{
-    // When the frame window is resized, the attached buffer will be destroyed by
-    // Xwayland, causing unexpected invalid previous and current window pixmaps.
-    // With the addition of multiple window buffers in Xwayland 1.21, X11 clients
-    // are no longer able to destroy the buffer after it's been committed and not
-    // released by the compositor yet.
-    static const quint32 xwaylandVersion = xcb_get_setup(kwinApp()->x11Connection())->release_number;
-    return xwaylandVersion >= 12100000;
-}
-
-} // namespace KWin
diff --git a/src/xwaylandwindow.h b/src/xwaylandwindow.h
deleted file mode 100644
index bb1929e8b6..0000000000
--- a/src/xwaylandwindow.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
-    KWin - the KDE window manager
-    This file is part of the KDE project.
-
-    SPDX-FileCopyrightText: 2020 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
-
-    SPDX-License-Identifier: GPL-2.0-or-later
-*/
-
-#pragma once
-
-#include "x11window.h"
-
-namespace KWin
-{
-
-/**
- * The XwaylandWindow class represents a managed Xwayland window.
- */
-class XwaylandWindow : public X11Window
-{
-    Q_OBJECT
-
-public:
-    explicit XwaylandWindow();
-
-    bool wantsSyncCounter() const override;
-
-private:
-    void associate();
-    void initialize();
-};
-
-} // namespace KWin