diff --git a/src/quick/items/qquickshadereffectsource.cpp b/src/quick/items/qquickshadereffectsource.cpp
index 547e2141f609c60842c673e69c79df2c26897d6c..2b613df0f22410e283c6982841c3e6f1a7b7ae18 100644
--- a/src/quick/items/qquickshadereffectsource.cpp
+++ b/src/quick/items/qquickshadereffectsource.cpp
@@ -955,6 +955,11 @@ QSGNode *QQuickShaderEffectSource::updatePaintNode(QSGNode *oldNode, UpdatePaint
                       ? QSize(qCeil(qAbs(sourceRect.width())), qCeil(qAbs(sourceRect.height())))
                       : m_textureSize;
     Q_ASSERT(!textureSize.isEmpty());
+
+    // Crate large textures on high-dpi displays.
+    if (sourceItem() && sourceItem()->window())
+        textureSize *= sourceItem()->window()->devicePixelRatio();
+
     QQuickItemPrivate *d = static_cast<QQuickItemPrivate *>(QObjectPrivate::get(this));
     const QSize minTextureSize = d->sceneGraphContext()->minimumFBOSize();
     // Keep power-of-two by doubling the size.
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 2ce91cdc2c9bcf9c7cc3bb71531810fef0a45e24..a915430616ea30ce658732333444821e51533fcf 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -336,14 +336,15 @@ void QQuickWindowPrivate::renderSceneGraph(const QSize &size)
     Q_Q(QQuickWindow);
     emit q->beforeRendering();
     int fboId = 0;
-    renderer->setDeviceRect(QRect(QPoint(0, 0), size));
+    const qreal devicePixelRatio = q->devicePixelRatio();
+    renderer->setDeviceRect(QRect(QPoint(0, 0), size * devicePixelRatio));
     if (renderTargetId) {
         fboId = renderTargetId;
         renderer->setViewportRect(QRect(QPoint(0, 0), renderTargetSize));
     } else {
-        renderer->setViewportRect(QRect(QPoint(0, 0), size));
+        renderer->setViewportRect(QRect(QPoint(0, 0), size * devicePixelRatio));
     }
-    renderer->setProjectionMatrixToDeviceRect();
+    renderer->setProjectionMatrixToRect(QRect(QPoint(0, 0), size));
 
     context->renderNextFrame(renderer, fboId);
     emit q->afterRendering();