diff --git a/scene.cpp b/scene.cpp
index 27da36e893..89eeeb9bb0 100644
--- a/scene.cpp
+++ b/scene.cpp
@@ -82,6 +82,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "thumbnailitem.h"
 
 #include <KWayland/Server/buffer_interface.h>
+#include <KWayland/Server/subcompositor_interface.h>
 #include <KWayland/Server/surface_interface.h>
 
 namespace KWin
@@ -937,6 +938,15 @@ WindowPixmap::WindowPixmap(Scene::Window *window)
 {
 }
 
+WindowPixmap::WindowPixmap(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface, WindowPixmap *parent)
+    : m_window(parent->m_window)
+    , m_pixmap(XCB_PIXMAP_NONE)
+    , m_discarded(false)
+    , m_parent(parent)
+    , m_subSurface(subSurface)
+{
+}
+
 WindowPixmap::~WindowPixmap()
 {
     if (isValid() && !kwinApp()->shouldUseWaylandForCompositing()) {
@@ -957,7 +967,7 @@ void WindowPixmap::create()
     if (kwinApp()->shouldUseWaylandForCompositing()) {
         // use Buffer
         updateBuffer();
-        if (m_buffer || !m_fbo.isNull()) {
+        if ((m_buffer || !m_fbo.isNull()) && m_subSurface.isNull()) {
             m_window->unreferencePreviousPixmap();
         }
         return;
@@ -991,6 +1001,12 @@ void WindowPixmap::create()
     m_window->unreferencePreviousPixmap();
 }
 
+WindowPixmap *WindowPixmap::createChild(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface)
+{
+    Q_UNUSED(subSurface)
+    return nullptr;
+}
+
 bool WindowPixmap::isValid() const
 {
     if (kwinApp()->shouldUseWaylandForCompositing()) {
@@ -1001,9 +1017,42 @@ bool WindowPixmap::isValid() const
 
 void WindowPixmap::updateBuffer()
 {
-    if (auto s = toplevel()->surface()) {
+    using namespace KWayland::Server;
+    SurfaceInterface *s = nullptr;
+    if (!m_subSurface.isNull()) {
+        s = m_subSurface->surface().data();
+    } else {
+        s = toplevel()->surface();
+    }
+    if (s) {
+        QVector<WindowPixmap*> oldTree = m_children;
+        QVector<WindowPixmap*> children;
         using namespace KWayland::Server;
+        const auto subSurfaces = s->childSubSurfaces();
+        for (const auto &subSurface : subSurfaces) {
+            if (subSurface.isNull()) {
+                continue;
+            }
+            auto it = std::find_if(oldTree.begin(), oldTree.end(), [subSurface] (WindowPixmap *p) { return p->m_subSurface == subSurface; });
+            if (it != oldTree.end()) {
+                children << *it;
+                (*it)->updateBuffer();
+                oldTree.erase(it);
+            } else {
+                WindowPixmap *p = createChild(subSurface);
+                if (p) {
+                    p->create();
+                    children << p;
+                }
+            }
+        }
+        setChildren(children);
+        qDeleteAll(oldTree);
         if (auto b = s->buffer()) {
+            if (b == m_buffer) {
+                // no change
+                return;
+            }
             if (m_buffer) {
                 QObject::disconnect(m_buffer.data(), &BufferInterface::aboutToBeDestroyed, m_buffer.data(), &BufferInterface::unref);
                 m_buffer->unref();
@@ -1011,6 +1060,12 @@ void WindowPixmap::updateBuffer()
             m_buffer = b;
             m_buffer->ref();
             QObject::connect(m_buffer.data(), &BufferInterface::aboutToBeDestroyed, m_buffer.data(), &BufferInterface::unref);
+        } else if (m_subSurface) {
+            if (m_buffer) {
+                QObject::disconnect(m_buffer.data(), &BufferInterface::aboutToBeDestroyed, m_buffer.data(), &BufferInterface::unref);
+                m_buffer->unref();
+                m_buffer.clear();
+            }
         } else {
             // might be an internal window
             const auto &fbo = toplevel()->internalFramebufferObject();
@@ -1018,6 +1073,12 @@ void WindowPixmap::updateBuffer()
                 m_fbo = fbo;
             }
         }
+    } else {
+        if (m_buffer) {
+            QObject::disconnect(m_buffer.data(), &BufferInterface::aboutToBeDestroyed, m_buffer.data(), &BufferInterface::unref);
+            m_buffer->unref();
+            m_buffer.clear();
+        }
     }
 }
 
diff --git a/scene.h b/scene.h
index 279f71394d..7eb1347da7 100644
--- a/scene.h
+++ b/scene.h
@@ -35,6 +35,7 @@ namespace KWayland
 namespace Server
 {
 class BufferInterface;
+class SubSurfaceInterface;
 }
 }
 
@@ -392,8 +393,31 @@ public:
      */
     Toplevel *toplevel() const;
 
+    /**
+     * @returns the parent WindowPixmap in the sub-surface tree
+     **/
+    WindowPixmap *parent() const {
+        return m_parent;
+    }
+
+    /**
+     * @returns the current sub-surface tree
+     **/
+    QVector<WindowPixmap*> children() const {
+        return m_children;
+    }
+
+    /**
+     * @returns the subsurface this WindowPixmap is for if it is not for a root window
+     **/
+    QPointer<KWayland::Server::SubSurfaceInterface> subSurface() const {
+        return m_subSurface;
+    }
+
 protected:
     explicit WindowPixmap(Scene::Window *window);
+    explicit WindowPixmap(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface, WindowPixmap *parent);
+    virtual WindowPixmap *createChild(const QPointer<KWayland::Server::SubSurfaceInterface> &subSurface);
     /**
      * @return The Window this WindowPixmap belongs to
      */
@@ -403,7 +427,15 @@ protected:
      * Should be called by the implementing subclasses when the Wayland Buffer changed and needs
      * updating.
      **/
-    void updateBuffer();
+    virtual void updateBuffer();
+
+    /**
+     * Sets the sub-surface tree to @p children.
+     **/
+    void setChildren(const QVector<WindowPixmap*> &children) {
+        m_children = children;
+    }
+
 private:
     Scene::Window *m_window;
     xcb_pixmap_t m_pixmap;
@@ -412,6 +444,9 @@ private:
     QRect m_contentsRect;
     QPointer<KWayland::Server::BufferInterface> m_buffer;
     QSharedPointer<QOpenGLFramebufferObject> m_fbo;
+    WindowPixmap *m_parent = nullptr;
+    QVector<WindowPixmap*> m_children;
+    QPointer<KWayland::Server::SubSurfaceInterface> m_subSurface;
 };
 
 class Scene::EffectFrame