diff --git a/lib/dns/xfrin.c b/lib/dns/xfrin.c
index 86aee0e21f..0f72656779 100644
--- a/lib/dns/xfrin.c
+++ b/lib/dns/xfrin.c
@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
-/* $Id: xfrin.c,v 1.80 2000/07/03 13:33:05 marka Exp $ */
+/* $Id: xfrin.c,v 1.81 2000/07/03 22:42:36 gson Exp $ */
 
 #include <config.h>
 
@@ -312,6 +312,12 @@ static isc_result_t
 ixfr_init(dns_xfrin_ctx_t *xfr) {
 	isc_result_t result;
 
+	if (xfr->reqtype != dns_rdatatype_ixfr) {
+		xfrin_log(xfr, ISC_LOG_ERROR, 
+			  "got incremental response to AXFR request");
+		return (DNS_R_FORMERR);
+	}
+
 	xfr->is_ixfr = ISC_TRUE;
 	INSIST(xfr->db != NULL);
 	xfr->difflen = 0;
@@ -443,8 +449,7 @@ xfr_rr(dns_xfrin_ctx_t *xfr, dns_name_t *name, isc_uint32_t ttl,
 		 * If the transfer begins with one SOA record, it is an AXFR,
 		 * if it begins with two SOAs, it is an IXFR.
 		 */
-		if (xfr->reqtype == dns_rdatatype_ixfr &&
-		    rdata->type == dns_rdatatype_soa &&
+		if (rdata->type == dns_rdatatype_soa &&
 		    xfr->ixfr.request_serial == dns_soa_getserial(rdata)) {
 			xfrin_log(xfr, ISC_LOG_DEBUG(3),
 				  "got incremental response");