diff --git a/app/crm/utils/Util.php b/app/crm/utils/Util.php
index 0701f5e..7bf4efd 100644
--- a/app/crm/utils/Util.php
+++ b/app/crm/utils/Util.php
@@ -126,7 +126,7 @@ class Util
 
     public static function mask($str)
     {
-        $length = strlen($str);
+        $length = mb_strlen($str);
 
         if(empty($str)){
             return '';