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
@@ -49,6 +49,7 @@
     void testCursorMoving();
     void testWindow_data();
     void testWindow();
+    void testWindowScaled();
     void testCompositorRestart_data();
     void testCompositorRestart();
 };
@@ -190,6 +191,44 @@
     QCOMPARE(referenceImage, *scene->backend()->buffer());
 }
 
+void SceneQPainterTest::testWindowScaled()
+{
+    KWin::Cursor::setPos(10, 10);
+    // this test verifies that a window is rendered correctly
+    using namespace KWayland::Client;
+    QVERIFY(Test::waitForWaylandPointer());
+    QScopedPointer<Surface> s(Test::createSurface());
+    QScopedPointer<ShellSurface> ss(Test::createShellSurface(s.data()));
+    QScopedPointer<Pointer> p(Test::waylandSeat()->createPointer());
+
+    auto scene = qobject_cast<SceneQPainter*>(KWin::Compositor::self()->scene());
+    QVERIFY(scene);
+    QSignalSpy frameRenderedSpy(scene, &Scene::frameRendered);
+    QVERIFY(frameRenderedSpy.isValid());
+
+    // now let's set a cursor image
+    QScopedPointer<Surface> cs(Test::createSurface());
+    QVERIFY(!cs.isNull());
+    Test::render(cs.data(), QSize(10, 10), Qt::red);
+    p->setCursor(cs.data(), QPoint(5, 5));
+
+    // now let's map the window
+    s->setScale(2);
+    QVERIFY(Test::renderAndWaitForShown(s.data(), QSize(400, 600), Qt::blue));
+
+    // which should trigger a frame
+    if (frameRenderedSpy.isEmpty()) {
+        QVERIFY(frameRenderedSpy.wait());
+    }
+    QImage referenceImage(QSize(1280, 1024), QImage::Format_RGB32);
+    referenceImage.fill(Qt::black);
+    QPainter painter(&referenceImage);
+    painter.fillRect(0, 0, 200, 300, Qt::blue);
+    painter.fillRect(5, 5, 10, 10, Qt::red); //cursor
+
+    QCOMPARE(referenceImage, *scene->backend()->buffer());
+}
+
 void SceneQPainterTest::testCompositorRestart_data()
 {
     QTest::addColumn<Test::ShellSurfaceType>("type");
diff --git a/plugins/platforms/x11/windowed/scene_qpainter_x11_backend.cpp b/plugins/platforms/x11/windowed/scene_qpainter_x11_backend.cpp
--- a/plugins/platforms/x11/windowed/scene_qpainter_x11_backend.cpp
+++ b/plugins/platforms/x11/windowed/scene_qpainter_x11_backend.cpp
@@ -46,7 +46,7 @@
     for (int i = 0; i < screens()->count(); ++i) {
         Output *output = new Output;
         output->window = m_backend->windowForScreen(i);
-        output->buffer = QImage(screens()->size(i), QImage::Format_RGB32);
+        output->buffer = QImage(screens()->size(i) * screens()->scale(i), QImage::Format_RGB32);
         output->buffer.fill(Qt::black);
         m_outputs << output;
     }
diff --git a/plugins/platforms/x11/windowed/x11windowed_backend.cpp b/plugins/platforms/x11/windowed/x11windowed_backend.cpp
--- a/plugins/platforms/x11/windowed/x11windowed_backend.cpp
+++ b/plugins/platforms/x11/windowed/x11windowed_backend.cpp
@@ -127,10 +127,11 @@
             XCB_EVENT_MASK_STRUCTURE_NOTIFY |
             XCB_EVENT_MASK_EXPOSURE
         };
-        o.size = initialWindowSize();
+        o.scale = initialOutputScale();
+        o.size = initialWindowSize() * o.scale;
         if (!m_windows.isEmpty()) {
             const auto &p = m_windows.last();
-            o.internalPosition = QPoint(p.internalPosition.x() + p.size.width(), 0);
+            o.internalPosition = QPoint(p.internalPosition.x() + p.size.width() / p.scale, 0);
         }
         xcb_create_window(m_connection, XCB_COPY_FROM_PARENT, o.window, m_screen->root,
                         0, 0, o.size.width(), o.size.height(),
@@ -388,11 +389,11 @@
     QSize s = QSize(event->width, event->height);
     if (s != (*it).size) {
         (*it).size = s;
-        int x = (*it).internalPosition.x() + s.width();
+        int x = (*it).internalPosition.x() + (*it).size.width() / (*it).scale;
         it++;
         for (; it != m_windows.end(); ++it) {
             (*it).internalPosition.setX(x);
-            x += (*it).size.width();
+            x += (*it).size.width() / (*it).scale;
         }
         emit sizeChanged();
     }
diff --git a/scene_qpainter.cpp b/scene_qpainter.cpp
--- a/scene_qpainter.cpp
+++ b/scene_qpainter.cpp
@@ -253,7 +253,8 @@
     if (!pixmap->subSurface().isNull()) {
         p += pixmap->subSurface()->position();
     }
-    painter->drawImage(p, pixmap->image());
+
+    painter->drawImage(QRect(pos, pixmap->size()), pixmap->image());
     const auto &children = pixmap->children();
     for (auto it = children.begin(); it != children.end(); ++it) {
         auto pixmap = static_cast<QPainterWindowPixmap*>(*it);