diff --git a/ChangeLog b/ChangeLog
index 900ef9d62a..34a226c04e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Mar 24 22:23:33 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
+
+	* doc/extention.rdoc: move from toplevel document and added extname.
+	* doc/extention.ja.rdoc: ditto.
+
 Tue Mar 24 22:06:58 2015  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* doc/standard_library.rdoc: strip.
diff --git a/README.EXT.ja b/doc/extention.ja.rdoc
similarity index 100%
rename from README.EXT.ja
rename to doc/extention.ja.rdoc
diff --git a/README.EXT b/doc/extention.rdoc
similarity index 100%
rename from README.EXT
rename to doc/extention.rdoc