diff --git a/services/core/java/com/android/server/notification/NotificationManagerService.java b/services/core/java/com/android/server/notification/NotificationManagerService.java
index ce94220ca1a19..73850de8681e4 100644
--- a/services/core/java/com/android/server/notification/NotificationManagerService.java
+++ b/services/core/java/com/android/server/notification/NotificationManagerService.java
@@ -3898,7 +3898,9 @@ public class NotificationManagerService extends SystemService {
         @Override
         public void onUserSwitched(int user) {
             synchronized (mNotificationList) {
-                for (ManagedServiceInfo info : mServices) {
+                int i = mServices.size()-1;
+                while (i --> 0) {
+                    final ManagedServiceInfo info = mServices.get(i);
                     unregisterService(info.service, info.userid);
                 }
             }