diff --git a/htdocs/core/login/functions_ldap.php b/htdocs/core/login/functions_ldap.php
index d468c882b2d..2afe2f00340 100644
--- a/htdocs/core/login/functions_ldap.php
+++ b/htdocs/core/login/functions_ldap.php
@@ -164,9 +164,13 @@ function check_user_password_ldap($usertotest,$passwordtotest,$entitytotest)
 						if ($ldapdebug) print "DEBUG: pwdLastSet = ".dol_print_date($ldap->pwdlastset,'day')."<br>\n";
 						if ($ldapdebug) print "DEBUG: badPasswordTime = ".dol_print_date($ldap->badpwdtime,'day')."<br>\n";
 
-						// On recherche le user dolibarr en fonction de son SID ldap
-						$sid = $ldap->getObjectSid($login);
-						if ($ldapdebug) print "DEBUG: sid = ".$sid."<br>\n";
+						// On recherche le user dolibarr en fonction de son SID ldap (only for Active Directory)
+						$sid = null;
+						if ($conf->global->LDAP_SERVER_TYPE == "activedirectory")
+						{
+							$sid = $ldap->getObjectSid($login);
+							if ($ldapdebug) print "DEBUG: sid = ".$sid."<br>\n";
+						}
 
 						$usertmp=new User($db);
 						$resultFetchUser=$usertmp->fetch('',$login,$sid);