+++ ./lib/dns/resconf.c
@@ -227,7 +227,7 @@
 	}
 
 	address = isc_mem_get(mctx, sizeof(*address));
-	if (res->ai_addrlen > sizeof(address->type)) {
+	if ((size_t) res->ai_addrlen > sizeof(address->type)) {
 		isc_mem_put(mctx, address, sizeof(*address));
 		result = ISC_R_RANGE;
 		goto cleanup;