diff --git a/ppp/pppd/plugins/radius/clientid.c b/ppp/pppd/plugins/radius/clientid.c
index d49579c..91201b0 100644
--- a/ppp/pppd/plugins/radius/clientid.c
+++ b/ppp/pppd/plugins/radius/clientid.c
@@ -104,13 +104,13 @@ int rc_read_mapfile(char *filename)
 UINT4 rc_map2id(char *name)
 {
 	struct map2id_s *p;
-	char ttyname[PATH_MAX];
+	char ttyname[PATH_MAX + 1];
 
 	*ttyname = '\0';
 	if (*name != '/')
 		strcpy(ttyname, "/dev/");
 
-	strncat(ttyname, name, sizeof(ttyname));
+	strlcat(ttyname, name, sizeof(ttyname));
 
 	for(p = map2id_list; p; p = p->next)
 		if (!strcmp(ttyname, p->name)) return p->id;