diff --git a/tests/unit/java/com/android/server/VpnManagerServiceTest.java b/tests/unit/java/com/android/server/VpnManagerServiceTest.java
index c8a93a6..deb56ef 100644
--- a/tests/unit/java/com/android/server/VpnManagerServiceTest.java
+++ b/tests/unit/java/com/android/server/VpnManagerServiceTest.java
@@ -131,6 +131,11 @@
                 Vpn vpn, VpnProfile profile) {
             return mLockdownVpnTracker;
         }
+
+        @Override
+        public @UserIdInt int getMainUserId() {
+            return UserHandle.USER_SYSTEM;
+        }
     }
 
     @Before