diff --git a/lib/dns/catz.c b/lib/dns/catz.c
index fd24410594..b755e6cce5 100644
--- a/lib/dns/catz.c
+++ b/lib/dns/catz.c
@@ -2167,8 +2167,8 @@ dns_catz_update_from_db(dns_db_t *db, dns_catz_zones_t *catzs) {
 
 	isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_MASTER,
 		      ISC_LOG_INFO,
-		      "catz: updating catalog zone '%s' with serial %d", bname,
-		      vers);
+		      "catz: updating catalog zone '%s' with serial %" PRIu32,
+		      bname, vers);
 
 	result = dns_catz_new_zone(catzs, &newzone, &db->origin);
 	if (result != ISC_R_SUCCESS) {