diff --git a/core/java/android/os/UserManager.java b/core/java/android/os/UserManager.java
index af9e592f9036d..e92e435fa7339 100644
--- a/core/java/android/os/UserManager.java
+++ b/core/java/android/os/UserManager.java
@@ -2370,6 +2370,8 @@ public class UserManager {
 
     /**
      * Return the number of users currently created on the device.
+     * <p>This API is not for use by third-party apps. It requires the {@code MANAGE_USERS}
+     * permission.</p>
      */
     public int getUserCount() {
         List<UserInfo> users = getUsers();