diff --git a/ChangeLog b/ChangeLog
index b4d3d1ef60..ea884c3015 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,8 @@
 Mon Sep  2 14:39:29 2013  Akinori MUSHA  <knu@iDaemons.org>
 
-	* ruby.c (Process#setproctitle): Fix and improve rdoc.
+	* ruby.c (Process#setproctitle): [DOC] Fix and improve rdoc.
 
-	* ruby.c (Process#argv0): Improve rdoc.
+	* ruby.c (Process#argv0): [DOC] Improve rdoc.
 
 Mon Sep  2 14:15:00 2013  Kenta Murata  <mrkn@cookpad.com>