diff --git a/lib/dns/rdataset.c b/lib/dns/rdataset.c
index ebc27843ac..3e2e433129 100644
--- a/lib/dns/rdataset.c
+++ b/lib/dns/rdataset.c
@@ -261,6 +261,12 @@ dns_rdataset_towire(dns_rdataset_t *rdataset,
 		    dns_compress_t *cctx,
 		    isc_buffer_t *target)
 {
+	dns_rdata_t rdata;
+	isc_region_t r;
+	dns_rdataclass_t rclass;
+	dns_rdatatype_t rtype;
+	dns_ttl_t rttl;
+	dns_result_t result;
 
 	/*
 	 * Convert 'rdataset' to wire format, compressing names as specified
@@ -268,11 +274,56 @@ dns_rdataset_towire(dns_rdataset_t *rdataset,
 	 */
 
 	REQUIRE(DNS_RDATASET_VALID(rdataset));
+	result = dns_rdataset_first(rdataset);
+	REQUIRE(result == DNS_R_SUCCESS);
 
-	/* XXX stop warnings. */
-	owner_name = NULL;
-	cctx = NULL;
-	target = NULL;
+	do {
+		/*
+		 * copy out the name, type, class, ttl.
+		 */
+		result = dns_name_towire(owner_name, cctx, target);
+		if (result != DNS_R_SUCCESS)
+			return (result);
+		isc_buffer_available(target, &r);
+		if (r.length < (sizeof(dns_rdataclass_t)
+				+ sizeof(dns_rdatatype_t)
+				+ sizeof(dns_ttl_t)
+				+ 2)) /* XXX 2? it's for the rdata length */
+			return (DNS_R_NOSPACE);
+		rtype = rdataset->type;
+		r.base[0] = (rtype & 0xff00) >> 8;
+		r.base[1] = (rtype & 0xff);
+		rclass = rdataset->class;
+		r.base[2] = (rclass & 0xff00) >> 8;
+		r.base[3] = (rclass & 0x00ff);
+		rttl = rdataset->ttl;
+		r.base[4] = (rttl & 0xff000000) >> 24;
+		r.base[5] = (rttl & 0x00ff0000) >> 16;
+		r.base[6] = (rttl & 0x0000ff00) >> 8;
+		r.base[7] = (rttl & 0x000000ff);
+		isc_buffer_add(target, (sizeof(dns_rdataclass_t)
+					+ sizeof(dns_rdatatype_t)
+					+ sizeof(dns_ttl_t)
+					+ 2)); /* XXX see XXX above */
+		/*
+		 * copy out the rdata length
+		 */
+		dns_rdataset_current(rdataset, &rdata);
+		r.base[8] = (rdata.length & 0xff00) >> 8;
+		r.base[9] = (rdata.length & 0x00ff);
 
-	return (DNS_R_NOTIMPLEMENTED);
+		/*
+		 * copy out the rdata
+		 */
+		result = dns_rdata_towire(&rdata, cctx, target);
+		if (result != DNS_R_SUCCESS)
+			return (result);
+
+		result = dns_rdataset_next(rdataset);
+	} while (result == DNS_R_SUCCESS);
+
+	if (result != DNS_R_NOMORE)
+		return (result);
+
+	return (DNS_R_SUCCESS);
 }