diff --git a/login/signup.php b/login/signup.php
index 71dab6d..a1fbc7a 100644
--- a/login/signup.php
+++ b/login/signup.php
@@ -22,6 +22,7 @@
         $user->firstaccess = time();
         $user->secret      = random_string(15);
         $user->auth        = $CFG->auth;
+        $user = (object)truncate_userinfo ((array)$user);
 
         if (!empty($CFG->auth_user_create) and function_exists('auth_user_create') ){
             if (! auth_user_exists($user->username)) {