diff --git a/zmldapsync/zmldapsync.pl b/zmldapsync/zmldapsync.pl
index 080461e..fc2707a 100644
--- a/zmldapsync/zmldapsync.pl
+++ b/zmldapsync/zmldapsync.pl
@@ -797,7 +797,7 @@ sub build_domain_attrs {
 #  if ( defined $domain_conf->{users}->{filter} ) {
 #    $attrs = " zimbraAuthLdapSearchFilter " . zim_attr_value( "(&(|(" . $domain_conf->{users}->{key} . "=%u)(" . $domain_conf->{users}->{key} . "=%n))(" . $domain_conf->{users}->{filter} . ")" );
 #  }
-  $attrs .= " zimbraAuthLdapURL " .
+  $attrs .= " +zimbraAuthLdapURL " .
             join( ' +zimbraAuthLdapURL ', @{ $domain_conf->{ldap}->{servers} } );
   if ( defined $domain_conf->{ldap}->{start_tls} and
        yaml_bool( $domain_conf->{ldap}->{start_tls} ) ) {