diff --git a/src/dnssec.c b/src/dnssec.c
index 6490bc5e..5eb3767c 100644
--- a/src/dnssec.c
+++ b/src/dnssec.c
@@ -1554,7 +1554,7 @@ static int _getdns_verify_rrsig(const struct mem_funcs *mf,
 		for ( rdf = _getdns_rdf_iter_init(&rdf_spc, &val_rrset[i])
 		    ; rdf
 		    ; rdf = _getdns_rdf_iter_next(rdf) ) {
-			if (!(rdf->rdd_pos->type & GETDNS_RDF_N)) {
+			if ((rdf->rdd_pos->type & GETDNS_RDF_N) != GETDNS_RDF_N) {
 				gldns_buffer_write(
 				    &valbuf, rdf->pos, rdf->nxt - rdf->pos);
 				continue;