diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 26e37d6e0d975..421fd28cb2ed7 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -2033,7 +2033,7 @@ public class WindowManagerService extends IWindowManager.Stub
                     attrs.height = win.mAttrs.height;
                 }
 
-                flagChanges = win.mAttrs.flags ^= attrs.flags;
+                flagChanges = win.mAttrs.flags ^ attrs.flags;
                 attrChanges = win.mAttrs.copyFrom(attrs);
                 if ((attrChanges & (WindowManager.LayoutParams.LAYOUT_CHANGED
                         | WindowManager.LayoutParams.SYSTEM_UI_VISIBILITY_CHANGED)) != 0) {