diff --git a/lib/isc/unix/ifiter_sysctl.c b/lib/isc/unix/ifiter_sysctl.c
index 102ecc1fee..5aad3d2ab8 100644
--- a/lib/isc/unix/ifiter_sysctl.c
+++ b/lib/isc/unix/ifiter_sysctl.c
@@ -258,7 +258,8 @@ internal_current(isc_interfaceiter_t *iter) {
 
 		return (ISC_R_SUCCESS);
 	} else {
-		printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
+		printf("%s",
+		       isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
 				      ISC_MSG_UNEXPECTEDTYPE,
 				      "warning: unexpected interface list "
 				      "message type\n"));