diff --git a/app/Models/UserModel.php b/app/Models/UserModel.php
index f9fa704..c3795ce 100644
--- a/app/Models/UserModel.php
+++ b/app/Models/UserModel.php
@@ -11,7 +11,7 @@ class UserModel extends CommonModel
     protected $useAutoIncrement = false;
     protected $allowedFields    = ['uid', 'id', 'email', 'passwd', 'name',  'role', 'status', 'updated_at'];
     protected $validationRules      = [
-        'uid'               => 'if_exist|regex_match[/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/]',
+        'uid'               => 'required|regex_match[/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/]',
         'id'                => 'required|min_length[4]|max_length[20]',
         'passwd'            => 'required|trim|min_length[4]|max_length[150]',
         'name'              => 'required|min_length[2]|max_length[20]',