AttributeAssertion ava = ATTRIBUTEASSERTION_INIT;
                SlapReply rs = {REP_RESULT};
                op->o_callback = &cb;
-               cb.sc_response = slap_null_cb;
+               cb.sc_response = pam_compare_cb;
+               cb.sc_private = NULL;
                op->o_tag = LDAP_REQ_COMPARE;
                op->o_req_dn = ni->ni_pam_group_dn;
                op->o_req_ndn = ni->ni_pam_group_dn;
                ava.aa_value = dn;
                op->orc_ava = &ava;
                rc = op->o_bd->be_compare( op, &rs );
-               if ( rs.sr_err != LDAP_COMPARE_TRUE ) {
+               if ( cb.sc_private == NULL ) {
                        authzmsg = grpmsg;
                        rc = NSLCD_PAM_PERM_DENIED;
                        goto finish;