diff --git a/autotests/wayland/internal_window.cpp b/autotests/wayland/internal_window.cpp
--- a/autotests/wayland/internal_window.cpp
+++ b/autotests/wayland/internal_window.cpp
@@ -191,6 +191,16 @@
 
     kwinApp()->platform()->pointerMotion(QPoint(101, 50), timestamp++);
     QTRY_COMPARE(leaveSpy.count(), 1);
+
+    // set a mask on the window
+    win.setMask(QRegion(10, 20, 30, 40));
+    // outside the mask we should not get an enter
+    kwinApp()->platform()->pointerMotion(QPoint(5, 5), timestamp++);
+    QVERIFY(!enterSpy.wait(100));
+    QCOMPARE(enterSpy.count(), 1);
+    // inside the mask we should still get an enter
+    kwinApp()->platform()->pointerMotion(QPoint(25, 27), timestamp++);
+    QTRY_COMPARE(enterSpy.count(), 2);
 }
 
 void InternalWindowTest::testPointerPressRelease()
diff --git a/pointer_input.cpp b/pointer_input.cpp
--- a/pointer_input.cpp
+++ b/pointer_input.cpp
@@ -314,6 +314,11 @@
                     continue;
                 }
                 if (w->geometry().contains(m_pos.toPoint())) {
+                    // check input mask
+                    const QRegion mask = w->mask().translated(w->geometry().topLeft());
+                    if (!mask.isEmpty() && !mask.contains(m_pos.toPoint())) {
+                        continue;
+                    }
                     m_internalWindow = QPointer<QWindow>(w);
                     found = true;
                     break;