diff --git a/services/core/java/com/android/server/am/ActivityStarter.java b/services/core/java/com/android/server/am/ActivityStarter.java
index 9258539f4268b..e9b3e8d9a1963 100644
--- a/services/core/java/com/android/server/am/ActivityStarter.java
+++ b/services/core/java/com/android/server/am/ActivityStarter.java
@@ -966,7 +966,7 @@ class ActivityStarter {
             mService.mWindowManager.continueSurfaceLayout();
         }
 
-        postStartActivityProcessing(r, result, mSupervisor.mFocusedStack.mStackId,  mSourceRecord,
+        postStartActivityProcessing(r, result, mSupervisor.getLastStack().mStackId,  mSourceRecord,
                 mTargetStack);
 
         return result;