diff --git a/auth/ldap/auth.php b/auth/ldap/auth.php
index 1fd39092ba4..447b6a69d7f 100644
--- a/auth/ldap/auth.php
+++ b/auth/ldap/auth.php
@@ -1385,7 +1385,7 @@ class auth_plugin_ldap extends auth_plugin_base {
                 }
             }
         }
-        $moodleattributes['username'] = $this->config->user_attribute;
+        $moodleattributes['username'] = moodle_strtolower(trim($this->config->user_attribute));
         return $moodleattributes;
     }