diff --git a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
index dbb8272..9e29d49 100644
--- a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
+++ b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
@@ -1395,7 +1395,9 @@
         mActivityInterface.onTransitionCancelled(wasVisible);
 
         // Leave the pending invisible flag, as it may be used by wallpaper open animation.
-        mActivity.clearForceInvisibleFlag(INVISIBLE_BY_STATE_HANDLER);
+        if (mActivity != null) {
+            mActivity.clearForceInvisibleFlag(INVISIBLE_BY_STATE_HANDLER);
+        }
     }
 
     protected void switchToScreenshot() {