diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 8c07e01d11631..de858e39b8001 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -4463,7 +4463,9 @@ final class ActivityStack {
                     "moveTaskToBackAndShowHome");
         }
 
-        adjustFocusedActivityLocked(mResumedActivity, "moveTaskToBack");
+        // Using currently focused activity value from service instead of mResumedActivity,
+        // because if this happens when device is locked the mResumedActivity will be null.
+        adjustFocusedActivityLocked(mService.mFocusedActivity, "moveTaskToBack");
         mStackSupervisor.resumeFocusedStackTopActivityLocked();
         return true;
     }