diff --git a/autotests/integration/generic_scene_opengl_test.cpp b/autotests/integration/generic_scene_opengl_test.cpp
--- a/autotests/integration/generic_scene_opengl_test.cpp
+++ b/autotests/integration/generic_scene_opengl_test.cpp
@@ -79,6 +79,7 @@
     auto scene = KWin::Compositor::self()->scene();
     QVERIFY(scene);
     QCOMPARE(scene->compositingType(), KWin::OpenGL2Compositing);
+    QCOMPARE(kwinApp()->platform()->selectedCompositor(), KWin::OpenGLCompositing);
 }
 
 void GenericSceneOpenGLTest::testRestart_data()
@@ -109,6 +110,7 @@
     auto scene = KWin::Compositor::self()->scene();
     QVERIFY(scene);
     QCOMPARE(scene->compositingType(), KWin::OpenGL2Compositing);
+    QCOMPARE(kwinApp()->platform()->selectedCompositor(), KWin::OpenGLCompositing);
 
     // trigger a repaint
     KWin::Compositor::self()->addRepaintFull();
diff --git a/autotests/integration/scene_qpainter_test.cpp b/autotests/integration/scene_qpainter_test.cpp
--- a/autotests/integration/scene_qpainter_test.cpp
+++ b/autotests/integration/scene_qpainter_test.cpp
@@ -108,6 +108,7 @@
     Compositor::self()->addRepaintFull();
     auto scene = Compositor::self()->scene();
     QVERIFY(scene);
+    QCOMPARE(kwinApp()->platform()->selectedCompositor(), QPainterCompositing);
     QSignalSpy frameRenderedSpy(scene, &Scene::frameRendered);
     QVERIFY(frameRenderedSpy.isValid());
     QVERIFY(frameRenderedSpy.wait());
diff --git a/composite.cpp b/composite.cpp
--- a/composite.cpp
+++ b/composite.cpp
@@ -260,6 +260,8 @@
         return;
     }
 
+    kwinApp()->platform()->setSelectedCompositor(m_scene->compositingType() & OpenGLCompositing ? OpenGLCompositing : m_scene->compositingType());
+
     if (!Workspace::self() && m_scene && m_scene->compositingType() == QPainterCompositing) {
         // Force Software QtQuick on first startup with QPainter
         QQuickWindow::setSceneGraphBackend(QSGRendererInterface::Software);
diff --git a/platform.h b/platform.h
--- a/platform.h
+++ b/platform.h
@@ -430,6 +430,25 @@
      **/
     virtual QString supportInformation() const;
 
+    /**
+     * The compositor plugin which got selected from @link{supportedCompositors}.
+     * Prior to selecting a compositor this returns @c NoCompositing.
+     *
+     * This method allows the platforms to limit the offerings in @link{supportedCompositors}
+     * in case they do not support runtime compositor switching
+     **/
+    CompositingType selectedCompositor() const
+    {
+        return m_selectedCompositor;
+    }
+    /**
+     * Used by Compositor to set the used compositor.
+     **/
+    void setSelectedCompositor(CompositingType type)
+    {
+        m_selectedCompositor = type;
+    }
+
 public Q_SLOTS:
     void pointerMotion(const QPointF &position, quint32 time);
     void pointerButtonPressed(quint32 button, quint32 time);
@@ -531,6 +550,7 @@
     int m_hideCursorCounter = 0;
     ColorCorrect::Manager *m_colorCorrect = nullptr;
     bool m_supportsGammaControl = false;
+    CompositingType m_selectedCompositor = NoCompositing;
 };
 
 }
diff --git a/plugins/platforms/drm/drm_backend.cpp b/plugins/platforms/drm/drm_backend.cpp
--- a/plugins/platforms/drm/drm_backend.cpp
+++ b/plugins/platforms/drm/drm_backend.cpp
@@ -769,6 +769,9 @@
 
 QVector<CompositingType> DrmBackend::supportedCompositors() const
 {
+    if (selectedCompositor() != NoCompositing) {
+        return {selectedCompositor()};
+    }
 #if HAVE_GBM
     return QVector<CompositingType>{OpenGLCompositing, QPainterCompositing};
 #else
diff --git a/plugins/platforms/virtual/virtual_backend.h b/plugins/platforms/virtual/virtual_backend.h
--- a/plugins/platforms/virtual/virtual_backend.h
+++ b/plugins/platforms/virtual/virtual_backend.h
@@ -58,6 +58,9 @@
     Outputs enabledOutputs() const override;
 
     QVector<CompositingType> supportedCompositors() const override {
+        if (selectedCompositor() != NoCompositing) {
+            return {selectedCompositor()};
+        }
         return QVector<CompositingType>{OpenGLCompositing, QPainterCompositing};
     }
 
diff --git a/plugins/platforms/wayland/wayland_backend.cpp b/plugins/platforms/wayland/wayland_backend.cpp
--- a/plugins/platforms/wayland/wayland_backend.cpp
+++ b/plugins/platforms/wayland/wayland_backend.cpp
@@ -655,6 +655,9 @@
 
 QVector<CompositingType> WaylandBackend::supportedCompositors() const
 {
+    if (selectedCompositor() != NoCompositing) {
+        return {selectedCompositor()};
+    }
 #if HAVE_WAYLAND_EGL
     return QVector<CompositingType>{OpenGLCompositing, QPainterCompositing};
 #else
diff --git a/plugins/platforms/x11/windowed/x11windowed_backend.h b/plugins/platforms/x11/windowed/x11windowed_backend.h
--- a/plugins/platforms/x11/windowed/x11windowed_backend.h
+++ b/plugins/platforms/x11/windowed/x11windowed_backend.h
@@ -70,6 +70,9 @@
     void warpPointer(const QPointF &globalPos) override;
 
     QVector<CompositingType> supportedCompositors() const override {
+        if (selectedCompositor() != NoCompositing) {
+            return {selectedCompositor()};
+        }
         return QVector<CompositingType>{OpenGLCompositing, QPainterCompositing};
     }