diff --git a/services/core/java/com/android/server/wm/ActivityStarter.java b/services/core/java/com/android/server/wm/ActivityStarter.java
index 0d447e34502e7..c1e1a39dd09bf 100644
--- a/services/core/java/com/android/server/wm/ActivityStarter.java
+++ b/services/core/java/com/android/server/wm/ActivityStarter.java
@@ -1797,7 +1797,8 @@ class ActivityStarter {
         }
 
         // Get top task at beginning because the order may be changed when reusing existing task.
-        final Task prevTopTask = mPreferredTaskDisplayArea.getFocusedRootTask();
+        final Task prevTopRootTask = mPreferredTaskDisplayArea.getFocusedRootTask();
+        final Task prevTopTask = prevTopRootTask != null ? prevTopRootTask.getTopLeafTask() : null;
         final Task reusedTask = getReusableTask();
 
         // If requested, freeze the task list