diff --git a/bin/check/named-checkconf.c b/bin/check/named-checkconf.c
index 204bd1fffc..ceba9adce3 100644
--- a/bin/check/named-checkconf.c
+++ b/bin/check/named-checkconf.c
@@ -246,9 +246,7 @@ configure_zone(const char *vclass, const char *view, const cfg_obj_t *zconfig,
 	 * Skip checks when using an alternate data source.
 	 */
 	cfg_map_get(zoptions, "database", &dbobj);
-	if (dbobj != NULL && strcmp("rbt", cfg_obj_asstring(dbobj)) != 0 &&
-	    strcmp("rbt64", cfg_obj_asstring(dbobj)) != 0)
-	{
+	if (dbobj != NULL && strcmp("rbt", cfg_obj_asstring(dbobj)) != 0) {
 		return (ISC_R_SUCCESS);
 	}
 
diff --git a/bin/named/server.c b/bin/named/server.c
index e2de427746..776e170384 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -1779,10 +1779,6 @@ check_dbtype(dns_zone_t *zone, unsigned int dbtypec, const char **dbargv,
 	for (i = 0; i < dbtypec; i++) {
 		if (argv[i] == NULL || strcmp(argv[i], dbargv[i]) != 0) {
 			CHECK(ISC_R_FAILURE);
-
-			/*
-			 * Check that there are not extra arguments.
-			 */
 		}
 	}
 
diff --git a/lib/bind9/check.c b/lib/bind9/check.c
index 8a2b645c79..658daec76d 100644
--- a/lib/bind9/check.c
+++ b/lib/bind9/check.c
@@ -3738,7 +3738,7 @@ check_zoneconf(const cfg_obj_t *zconfig, const cfg_obj_t *voptions,
 	}
 
 	/*
-	 * If the zone type is rbt/rbt64 then primary/hint zones require file
+	 * If the zone type is rbt then primary/hint zones require file
 	 * clauses. If inline-signing is used, then secondary zones require a
 	 * file clause as well.
 	 */
@@ -3759,8 +3759,7 @@ check_zoneconf(const cfg_obj_t *zconfig, const cfg_obj_t *voptions,
 		result = ISC_R_FAILURE;
 	} else if (!dlz && (tresult == ISC_R_NOTFOUND ||
 			    (tresult == ISC_R_SUCCESS &&
-			     (strcmp("rbt", cfg_obj_asstring(obj)) == 0 ||
-			      strcmp("rbt64", cfg_obj_asstring(obj)) == 0))))
+			     strcmp("rbt", cfg_obj_asstring(obj)) == 0)))
 	{
 		isc_result_t res1;
 		const cfg_obj_t *fileobj = NULL;
diff --git a/lib/dns/rbtdb.h b/lib/dns/rbtdb.h
index 44e51023ab..8edee5b3eb 100644
--- a/lib/dns/rbtdb.h
+++ b/lib/dns/rbtdb.h
@@ -34,8 +34,8 @@ dns_rbtdb_create(isc_mem_t *mctx, const dns_name_t *base, dns_dbtype_t type,
 		 void *driverarg, dns_db_t **dbp);
 
 /*%<
- * Create a new database of type "rbt" (or "rbt64").  Called via
- * dns_db_create(); see documentation for that function for more details.
+ * Create a new database of type "rbt". Called via dns_db_create();
+ * see documentation for that function for more details.
  *
  * If argv[0] is set, it points to a valid memory context to be used for
  * allocation of heap memory.  Generally this is used for cache databases
diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 794154d8b5..2c011c0241 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -1924,9 +1924,7 @@ dns_zone_rpz_enable(dns_zone_t *zone, dns_rpz_zones_t *rpzs,
 	 * Only zones that are loaded instead of mmap()ed create the
 	 * summary data and so can be policy zones.
 	 */
-	if (strcmp(zone->db_argv[0], "rbt") != 0 &&
-	    strcmp(zone->db_argv[0], "rbt64") != 0)
-	{
+	if (strcmp(zone->db_argv[0], "rbt") != 0) {
 		return (ISC_R_NOTIMPLEMENTED);
 	}
 
@@ -2163,8 +2161,7 @@ zone_load(dns_zone_t *zone, unsigned int flags, bool locked) {
 
 	INSIST(zone->db_argc >= 1);
 
-	rbt = strcmp(zone->db_argv[0], "rbt") == 0 ||
-	      strcmp(zone->db_argv[0], "rbt64") == 0;
+	rbt = strcmp(zone->db_argv[0], "rbt") == 0;
 
 	if (zone->db != NULL && zone->masterfile == NULL && rbt) {
 		/*