diff --git a/ChangeLog b/ChangeLog
index 2c4b618a92..a16e823c0d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Sep  5 20:59:30 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
+
+	* insns.def: change encoding pragma for emacs (shift_jis to utf-8).
+
 Mon Sep  5 19:32:15 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
 
 	* Makefile.in (INSNS): change command line option -Ks to -Ku for
diff --git a/insns.def b/insns.def
index a3bec2f434..2b4c3dbf99 100644
--- a/insns.def
+++ b/insns.def
@@ -1,4 +1,4 @@
-/** ##skip -*- mode:c; style:ruby; coding: shift_jis -*-
+/** ##skip -*- mode:c; style:ruby; coding: utf-8 -*-
   insns.def - YARV instruction definitions
 
   $Author: $