diff --git a/lib/dns/name.c b/lib/dns/name.c
index 5d2aae4a07..23bcdf6998 100644
--- a/lib/dns/name.c
+++ b/lib/dns/name.c
@@ -1612,7 +1612,7 @@ dns_name_tofilenametext(dns_name_t *name, isc_boolean_t omit_final_dot,
 					trem--;
 					nlen--;
 				} else {
-					if (trem < 3)
+					if (trem < 4)
 						return (ISC_R_NOSPACE);
 					snprintf(tdata, trem, "%%%02X", c);
 					tdata += 3;
diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 65c3dddb3c..6834067400 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -1300,12 +1300,14 @@ dns_zone_getdbtype(dns_zone_t *zone, char ***argv, isc_mem_t *mctx) {
 		size += strlen(zone->db_argv[i]) + 1;
 	mem = isc_mem_allocate(mctx, size);
 	if (mem != NULL) {
+		size_t remaining;
 		tmp = mem;
 		tmp2 = mem;
 		tmp2 += (zone->db_argc + 1) * sizeof(char *);
 		for (i = 0; i < zone->db_argc; i++) {
+			remaining = (size_t)(mem - tmp2);
 			*tmp++ = tmp2;
-			strlcpy(tmp2, zone->db_argv[i], size);
+			strlcpy(tmp2, zone->db_argv[i], remaining);
 			tmp2 += strlen(tmp2) + 1;
 		}
 		*tmp = NULL;