diff --git a/effects.cpp b/effects.cpp
index 0e62b63a9218ee7b594cad970230b74de1f6bf29..6b73b087d425a7f71d32f2dafac40ce0097e831a 100644
--- a/effects.cpp
+++ b/effects.cpp
@@ -1032,6 +1032,13 @@ EffectWindow* EffectsHandlerImpl::findWindow(WId id) const
         return w->effectWindow();
     if (Unmanaged* w = Workspace::self()->findUnmanaged(id))
         return w->effectWindow();
+#if HAVE_WAYLAND
+    if (waylandServer()) {
+        if (ShellClient *w = waylandServer()->findClient(id)) {
+            return w->effectWindow();
+        }
+    }
+#endif
     return NULL;
 }
 
diff --git a/shell_client.cpp b/shell_client.cpp
index 0b86f09612814759ead2f6a6308c0709e6c18ad9..13f0f8c2a15fc6c8fddd7f66313dae767019d8cf 100644
--- a/shell_client.cpp
+++ b/shell_client.cpp
@@ -22,10 +22,13 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "wayland_server.h"
 #include "virtualdesktops.h"
 
+#include <KWayland/Client/surface.h>
 #include <KWayland/Server/shell_interface.h>
 #include <KWayland/Server/surface_interface.h>
 #include <KWayland/Server/buffer_interface.h>
 
+#include <QWindow>
+
 using namespace KWayland::Server;
 
 namespace KWin
@@ -36,6 +39,8 @@ ShellClient::ShellClient(ShellSurfaceInterface *surface)
     , m_shellSurface(surface)
 {
     setSurface(surface->surface());
+    findInternalWindow();
+    createWindowId();
     setupCompositing();
     if (surface->surface()->buffer()) {
         setReadyForPainting();
@@ -43,7 +48,11 @@ ShellClient::ShellClient(ShellSurfaceInterface *surface)
     } else {
         ready_for_painting = false;
     }
-    setGeometry(QRect(QPoint(0, 0), m_clientSize));
+    if (m_internalWindow) {
+        setGeometry(m_internalWindow->geometry());
+    } else {
+        setGeometry(QRect(QPoint(0, 0), m_clientSize));
+    }
 
     setDesktop(VirtualDesktopManager::self()->current());
 
@@ -329,4 +338,31 @@ bool ShellClient::wantsInput() const
     return true;
 }
 
+void ShellClient::createWindowId()
+{
+    if (m_internalWindow) {
+        m_windowId = m_internalWindow->winId();
+    }
+    // TODO: create internal window ids
+}
+
+void ShellClient::findInternalWindow()
+{
+    if (m_shellSurface->client() != waylandServer()->qtConnection()) {
+        return;
+    }
+    const QWindowList windows = kwinApp()->topLevelWindows();
+    for (QWindow *w: windows) {
+        QScopedPointer<KWayland::Client::Surface> s(KWayland::Client::Surface::fromWindow(w));
+        if (!s) {
+            continue;
+        }
+        if (s->id() != surface()->id()) {
+            continue;
+        }
+        m_internalWindow = w;
+        return;
+    }
+}
+
 }
diff --git a/shell_client.h b/shell_client.h
index bd93ea24c403b21e8591b0c2fb0af00baa369e58..8ccb6c048120cdaed50eae836873de5b46a56e37 100644
--- a/shell_client.h
+++ b/shell_client.h
@@ -87,6 +87,10 @@ public:
     bool userCanSetNoBorder() const override;
     bool wantsInput() const override;
 
+    quint32 windowId() const {
+        return m_windowId;
+    }
+
 protected:
     void addDamage(const QRegion &damage) override;
     bool belongsToSameApplication(const AbstractClient *other, bool active_hack) const override;
@@ -94,11 +98,15 @@ protected:
 private:
     void setGeometry(const QRect &rect);
     void destroyClient();
+    void createWindowId();
+    void findInternalWindow();
     static void deleteClient(ShellClient *c);
 
     KWayland::Server::ShellSurfaceInterface *m_shellSurface;
     QSize m_clientSize;
     bool m_closing = false;
+    quint32 m_windowId = 0;
+    QWindow *m_internalWindow = nullptr;
 };
 
 }
diff --git a/wayland_server.cpp b/wayland_server.cpp
index c0a625a52ebee7876f2a0f372154d9649a08f9d0..9ae488440323d618d918b368e99f2966c02b6753 100644
--- a/wayland_server.cpp
+++ b/wayland_server.cpp
@@ -261,4 +261,20 @@ void WaylandServer::dispatch()
     m_display->dispatchEvents(0);
 }
 
+ShellClient *WaylandServer::findClient(quint32 id) const
+{
+    if (id == 0) {
+        return nullptr;
+    }
+    auto it = std::find_if(m_clients.constBegin(), m_clients.constEnd(),
+        [id] (ShellClient *c) {
+            return c->windowId() == id;
+        }
+    );
+    if (it == m_clients.constEnd()) {
+        return nullptr;
+    }
+    return *it;
+}
+
 }
diff --git a/wayland_server.h b/wayland_server.h
index 11c204f6b6d2fe10ca8db68595c71bdacdc8538c..18266d34efb6a00fcf8cb50d7a726a8ea0da7b7f 100644
--- a/wayland_server.h
+++ b/wayland_server.h
@@ -75,6 +75,7 @@ public:
         return m_clients;
     }
     void removeClient(ShellClient *c);
+    ShellClient *findClient(quint32 id) const;
 
     AbstractBackend *backend() const {
         return m_backend;
@@ -97,6 +98,9 @@ public:
     KWayland::Server::ClientConnection *xWaylandConnection() const {
         return m_xwaylandConnection;
     }
+    KWayland::Server::ClientConnection *qtConnection() const {
+        return m_qtConnection;
+    }
     KWayland::Server::ClientConnection *internalConnection() const {
         return m_internalConnection.server;
     }