diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 7d15587919e17..2dd25c969d0d3 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -1478,9 +1478,14 @@ public class WindowManagerService extends IWindowManager.Stub
                         rootType, attrs.token, attrs.packageName)) {
                     return WindowManagerGlobal.ADD_BAD_APP_TOKEN;
                 }
-                final IBinder binder = attrs.token != null ? attrs.token : client.asBinder();
-                token = new WindowToken(this, binder, type, false, displayContent,
-                        session.mCanAddInternalSystemWindow, isRoundedCornerOverlay);
+                if (hasParent) {
+                    // Use existing parent window token for child windows.
+                    token = parentWindow.mToken;
+                } else {
+                    final IBinder binder = attrs.token != null ? attrs.token : client.asBinder();
+                    token = new WindowToken(this, binder, type, false, displayContent,
+                            session.mCanAddInternalSystemWindow, isRoundedCornerOverlay);
+                }
             } else if (rootType >= FIRST_APPLICATION_WINDOW
                     && rootType <= LAST_APPLICATION_WINDOW) {
                 activity = token.asActivityRecord();
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowTokenTests.java b/services/tests/wmtests/src/com/android/server/wm/WindowTokenTests.java
index cef202cdc5d51..f185da3957547 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowTokenTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowTokenTests.java
@@ -84,6 +84,10 @@ public class WindowTokenTests extends WindowTestsBase {
         assertFalse(token.hasWindow(window12));
         assertTrue(token.hasWindow(window2));
         assertTrue(token.hasWindow(window3));
+
+        // The child windows should have the same window token as their parents.
+        assertEquals(window1.mToken, window11.mToken);
+        assertEquals(window1.mToken, window12.mToken);
     }
 
     @Test