diff --git a/bin/named/client.c b/bin/named/client.c
index 14d87775e7..af992256c3 100644
--- a/bin/named/client.c
+++ b/bin/named/client.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: client.c,v 1.107 2000/08/08 23:56:10 gson Exp $ */
+/* $Id: client.c,v 1.108 2000/08/21 23:45:05 bwelling Exp $ */
 
 #include <config.h>
 
@@ -991,6 +991,14 @@ client_request(isc_task_t *task, isc_event_t *event) {
 		}
 	}
 
+	if (client->message->rdclass == 0) {
+		ns_client_log(client, NS_LOGCATEGORY_CLIENT,
+			      NS_LOGMODULE_CLIENT, ISC_LOG_ERROR,
+			      "message class could not be determined");
+		ns_client_error(client, DNS_R_FORMERR);
+		goto cleanup_serverlock;
+	}
+
 	/*
 	 * Find a view that matches the client's source address.
 	 *