diff --git a/decorations/decoratedclient.h b/decorations/decoratedclient.h
index cb585cfe28..fb70d30259 100644
--- a/decorations/decoratedclient.h
+++ b/decorations/decoratedclient.h
@@ -28,6 +28,7 @@ namespace KWin
 {
 
 class Client;
+class AbstractClient;
 
 namespace Decoration
 {
@@ -78,7 +79,7 @@ public:
     void requestToggleOnAllDesktops() override;
     void requestToggleShade() override;
 
-    Client *client() {
+    AbstractClient *client() {
         return m_client;
     }
     Renderer *renderer() {
@@ -91,7 +92,7 @@ public:
 
 private:
     void createRenderer();
-    Client *m_client;
+    AbstractClient *m_client;
     Renderer *m_renderer;
 };
 
diff --git a/scene_opengl.cpp b/scene_opengl.cpp
index 3dd7fd959b..5f6c578c3d 100644
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -2429,7 +2429,7 @@ SceneOpenGLDecorationRenderer::SceneOpenGLDecorationRenderer(Decoration::Decorat
     : Renderer(client)
     , m_texture()
 {
-    connect(this, &Renderer::renderScheduled, client->client(), static_cast<void (Client::*)(const QRect&)>(&Client::addRepaint));
+    connect(this, &Renderer::renderScheduled, client->client(), static_cast<void (AbstractClient::*)(const QRect&)>(&AbstractClient::addRepaint));
 }
 
 SceneOpenGLDecorationRenderer::~SceneOpenGLDecorationRenderer() = default;
diff --git a/scene_qpainter.cpp b/scene_qpainter.cpp
index 0517662fe7..d9a8878496 100644
--- a/scene_qpainter.cpp
+++ b/scene_qpainter.cpp
@@ -571,7 +571,7 @@ bool SceneQPainterShadow::prepareBackend()
 SceneQPainterDecorationRenderer::SceneQPainterDecorationRenderer(Decoration::DecoratedClientImpl *client)
     : Renderer(client)
 {
-    connect(this, &Renderer::renderScheduled, client->client(), static_cast<void (Client::*)(const QRect&)>(&Client::addRepaint));
+    connect(this, &Renderer::renderScheduled, client->client(), static_cast<void (AbstractClient::*)(const QRect&)>(&AbstractClient::addRepaint));
 }
 
 SceneQPainterDecorationRenderer::~SceneQPainterDecorationRenderer() = default;
diff --git a/scene_xrender.cpp b/scene_xrender.cpp
index acf3d8f207..b5bb233c23 100644
--- a/scene_xrender.cpp
+++ b/scene_xrender.cpp
@@ -1173,7 +1173,7 @@ SceneXRenderDecorationRenderer::SceneXRenderDecorationRenderer(Decoration::Decor
     : Renderer(client)
     , m_gc(XCB_NONE)
 {
-    connect(this, &Renderer::renderScheduled, client->client(), static_cast<void (Client::*)(const QRect&)>(&Client::addRepaint));
+    connect(this, &Renderer::renderScheduled, client->client(), static_cast<void (AbstractClient::*)(const QRect&)>(&AbstractClient::addRepaint));
     for (int i = 0; i < int(DecorationPart::Count); ++i) {
         m_pixmaps[i] = XCB_PIXMAP_NONE;
         m_pictures[i] = nullptr;