diff --git a/inc/SP/Auth/Ldap/LdapStd.class.php b/inc/SP/Auth/Ldap/LdapStd.class.php
index e79564ea..56be2d05 100644
--- a/inc/SP/Auth/Ldap/LdapStd.class.php
+++ b/inc/SP/Auth/Ldap/LdapStd.class.php
@@ -73,7 +73,7 @@ class LdapStd extends LdapBase
     {
         $userLogin = ldap_escape($this->userLogin);
 
-        return '(&(|(samaccountname=' . $userLogin . ')(cn=' . $userLogin . ')(uid=' . $userLogin . '))(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject)))';
+        return '(&(|(samaccountname=' . $userLogin . ')(cn=' . $userLogin . ')(uid=' . $userLogin . ')(userPrincipalName=' . $userLogin . '))(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject)))';
     }
 
     /**
@@ -135,4 +135,4 @@ class LdapStd extends LdapBase
 
         return true;
     }
-}
\ No newline at end of file
+}