diff --git a/ChangeLog b/ChangeLog
index c9ddbf848c..b0c0f6da2e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Aug  3 00:12:00 2013  Masaki Matsushita  <glass.saga@gmail.com>
+
+	* NEWS: Add the description that IO#seek supports SEEK_DATA
+	  and SEEK_HOLE.
+
 Fri Aug  2 23:57:57 2013  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* vm.c (m_core_define_method, m_core_define_singleton_method): now
diff --git a/NEWS b/NEWS
index 35bda18840..d27ad0be0b 100644
--- a/NEWS
+++ b/NEWS
@@ -30,7 +30,8 @@ with all sufficient information, see the ChangeLog file.
 
 * IO
   * extended methods:
-    * IO#seek accepts symbols (:CUR, :END, :SET) for 2nd argument.
+    * IO#seek supports SEEK_DATA and SEEK_HOLE as whence.
+    * IO#seek accepts symbols (:CUR, :END, :SET, :DATA, :HOLE) for 2nd argument.
 
 * Kernel
   * New methods: