diff --git a/webapp/controller/UserController.class.php b/webapp/controller/UserController.class.php
index 9eb05681..fe7fc626 100644
--- a/webapp/controller/UserController.class.php
+++ b/webapp/controller/UserController.class.php
@@ -810,6 +810,13 @@ class UserController extends BaseAuthedController {
         $oldUser = User::findByAddress($address);
         if ($oldUser) {
             if ($oldUser['account_id'] != myself()->_getAccountId()) {
+                if (!phpcommon\isSameSeriesAccount(
+                    $oldUser['account_id'],
+                    myself()->_getAccountId()
+                )) {
+                    myself()->_rspErr(1, 'is not SameSeriesAccount');
+                    return;
+                }
                 User::updateOther(
                     $oldUser['account_id'],
                     array(