diff --git a/services/core/java/com/android/server/notification/NotificationManagerService.java b/services/core/java/com/android/server/notification/NotificationManagerService.java
index 4d05c36cff3a32a9be975640aa42ab7e564eeff0..4e029fde8bf57f09b2e14ef3f67763917285a98c 100755
--- a/services/core/java/com/android/server/notification/NotificationManagerService.java
+++ b/services/core/java/com/android/server/notification/NotificationManagerService.java
@@ -2291,7 +2291,7 @@ public class NotificationManagerService extends SystemService {
 
     @VisibleForTesting
     void clearNotifications() {
-        synchronized (mNotificationList) {
+        synchronized (mNotificationLock) {
             mEnqueuedNotifications.clear();
             mNotificationList.clear();
             mNotificationsByKey.clear();
@@ -2301,21 +2301,27 @@ public class NotificationManagerService extends SystemService {
 
     @VisibleForTesting
     void addNotification(NotificationRecord r) {
-        mNotificationList.add(r);
-        mNotificationsByKey.put(r.getSbn().getKey(), r);
-        if (r.getSbn().isGroup()) {
-            mSummaryByGroupKey.put(r.getGroupKey(), r);
+        synchronized (mNotificationLock) {
+            mNotificationList.add(r);
+            mNotificationsByKey.put(r.getSbn().getKey(), r);
+            if (r.getSbn().isGroup()) {
+                mSummaryByGroupKey.put(r.getGroupKey(), r);
+            }
         }
     }
 
     @VisibleForTesting
     void addEnqueuedNotification(NotificationRecord r) {
-        mEnqueuedNotifications.add(r);
+        synchronized (mNotificationLock) {
+            mEnqueuedNotifications.add(r);
+        }
     }
 
     @VisibleForTesting
     NotificationRecord getNotificationRecord(String key) {
-        return mNotificationsByKey.get(key);
+        synchronized (mNotificationLock) {
+            return mNotificationsByKey.get(key);
+        }
     }