diff --git a/lib/bind9/check.c b/lib/bind9/check.c
index 27843aca65..f47569100c 100644
--- a/lib/bind9/check.c
+++ b/lib/bind9/check.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: check.c,v 1.94 2008/11/16 20:57:55 marka Exp $ */
+/* $Id: check.c,v 1.95 2008/11/19 05:38:49 marka Exp $ */
 
 /*! \file */
 
@@ -799,7 +799,7 @@ check_options(const cfg_obj_t *options, isc_log_t *logctx, isc_mem_t *mctx) {
 	obj = NULL;
 	(void)cfg_map_get(options, "server-id", &obj);
 	if (obj != NULL && cfg_obj_isstring(obj) &&
-	    strlen(cfg_obj_asstring(obj)) > 1024) {
+	    strlen(cfg_obj_asstring(obj)) > 1024U) {
 		cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
 			    "'server-id' too big (>1024 bytes)");
 		result = ISC_R_FAILURE;