diff --git a/tests/manual/embeddedwindows/CMakeLists.txt b/tests/manual/embeddedwindows/CMakeLists.txt
new file mode 100644
index 00000000000..e25f14206e8
--- /dev/null
+++ b/tests/manual/embeddedwindows/CMakeLists.txt
@@ -0,0 +1,15 @@
+# Copyright (C) 2023 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+qt_internal_add_manual_test(embeddedwindows
+    SOURCES
+        main.cpp
+    LIBRARIES
+        Qt::Gui
+)
+
+if(APPLE)
+    enable_language(OBJCXX)
+    set_source_files_properties(main.cpp PROPERTIES LANGUAGE OBJCXX)
+    set_property(TARGET embeddedwindows PROPERTY PROPERTY MACOSX_BUNDLE TRUE)
+endif()
diff --git a/tests/manual/embeddedwindows/main.cpp b/tests/manual/embeddedwindows/main.cpp
new file mode 100644
index 00000000000..15c321839fe
--- /dev/null
+++ b/tests/manual/embeddedwindows/main.cpp
@@ -0,0 +1,102 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include <QtGui>
+
+#include "../../shared/nativewindow.h"
+
+#include <QDebug>
+
+class TestWindow : public QRasterWindow
+{
+public:
+    using QRasterWindow::QRasterWindow;
+    TestWindow(const QBrush &brush) : m_brush(brush) {}
+
+protected:
+    void mousePressEvent(QMouseEvent *) override
+    {
+        m_pressed = true;
+        update();
+    }
+
+    void mouseReleaseEvent(QMouseEvent *) override
+    {
+        m_pressed = false;
+        update();
+    }
+
+    void paintEvent(QPaintEvent *event) override
+    {
+        QPainter painter(this);
+        painter.setCompositionMode(QPainter::CompositionMode_Source);
+        painter.fillRect(event->rect(), m_pressed ? QGradient(QGradient::JuicyPeach) : m_brush);
+    }
+
+private:
+    QBrush m_brush = QGradient(QGradient::DustyGrass);
+    bool m_pressed = false;
+};
+
+int main(int argc, char *argv[])
+{
+    QGuiApplication app(argc, argv);
+
+    TestWindow window{QGradient(QGradient::WinterNeva)};
+    window.resize(500, 500);
+
+    TestWindow *opaqueChildWindow = new TestWindow;
+    opaqueChildWindow->setParent(&window);
+    opaqueChildWindow->setGeometry(50, 50, 100, 100);
+    opaqueChildWindow->showNormal();
+
+    TestWindow *maskedChildWindow = new TestWindow;
+    maskedChildWindow->setParent(&window);
+    maskedChildWindow->setGeometry(200, 50, 100, 100);
+    maskedChildWindow->setMask(QRegion(0, 0, 100, 100, QRegion::Ellipse));
+    maskedChildWindow->showNormal();
+
+    static const QColor transparentGreen = QColor(0, 255, 0, 20);
+    TestWindow *transparentChildWindow = new TestWindow(transparentGreen);
+    // The default surface format of a platform may not include
+    // an alpha, so set it explicitly.
+    QSurfaceFormat format = transparentChildWindow->format();
+    format.setAlphaBufferSize(8);
+    transparentChildWindow->setFormat(format);
+    // FIXME: Windows requires this, even for child windows
+    transparentChildWindow->setFlag(Qt::FramelessWindowHint);
+    transparentChildWindow->setParent(&window);
+    transparentChildWindow->setGeometry(350, 50, 100, 100);
+    transparentChildWindow->showNormal();
+
+    NativeWindow nativeWindow;
+    if (QWindow *foreignWindow = QWindow::fromWinId(nativeWindow)) {
+        foreignWindow->setParent(&window);
+        foreignWindow->setGeometry(50, 200, 100, 100);
+        foreignWindow->showNormal();
+    }
+
+    NativeWindow maskedNativeWindow;
+    if (QWindow *foreignWindow = QWindow::fromWinId(maskedNativeWindow)) {
+        foreignWindow->setParent(&window);
+        foreignWindow->setGeometry(200, 200, 100, 100);
+        foreignWindow->setMask(QRegion(0, 0, 100, 100, QRegion::Ellipse));
+        foreignWindow->showNormal();
+    }
+
+    NativeWindow nativeParentWindow;
+    if (QWindow *foreignWindow = QWindow::fromWinId(nativeParentWindow)) {
+        foreignWindow->setParent(&window);
+        foreignWindow->setGeometry(50, 350, 100, 100);
+        foreignWindow->showNormal();
+
+        TestWindow *maskedChildWindowOfNativeWindow = new TestWindow;
+        maskedChildWindowOfNativeWindow->setParent(foreignWindow);
+        maskedChildWindowOfNativeWindow->setGeometry(25, 25, 50, 50);
+        maskedChildWindowOfNativeWindow->showNormal();
+    }
+
+    window.show();
+
+    return app.exec();
+}
diff --git a/tests/shared/nativewindow.h b/tests/shared/nativewindow.h
index 75461d134d0..1ab5fc40ced 100644
--- a/tests/shared/nativewindow.h
+++ b/tests/shared/nativewindow.h
@@ -44,6 +44,10 @@ private:
 - (instancetype)init
 {
     if ((self = [super init])) {
+#if defined(Q_OS_MACOS)
+        self.wantsLayer = YES;
+#endif
+        self.layer.backgroundColor = CGColorCreateGenericRGB(1.0, 0.5, 1.0, 1.0);
     }
     return self;
 }
@@ -88,6 +92,7 @@ NativeWindow::NativeWindow()
         wc.lpfnWndProc = DefWindowProc;
         wc.hInstance = GetModuleHandle(nullptr);
         wc.lpszClassName = L"Native Window";
+        wc.hbrBackground = CreateSolidBrush(RGB(255, 128, 255));
         RegisterClass(&wc);
         return wc.lpszClassName;
     }();