diff --git a/ChangeLog b/ChangeLog
index 82a2fadb15..291ffbe392 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Sep 16 00:44:23 2013  Masaki Matsushita  <glass.saga@gmail.com>
+
+	* ext/socket/mkconstants.rb: define MSG_FASTOPEN.
+	  [ruby-core:57138] [Feature #8897]
+
 Sun Sep 15 13:31:23 2013  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* rational.c (nurat_div): reverted r28844, r28886 and r28887.
diff --git a/ext/socket/mkconstants.rb b/ext/socket/mkconstants.rb
index 73bc9feec0..d12b2a24e3 100644
--- a/ext/socket/mkconstants.rb
+++ b/ext/socket/mkconstants.rb
@@ -453,6 +453,7 @@ MSG_RST
 MSG_ERRQUEUE	nil	Fetch message from error queue
 MSG_NOSIGNAL	nil	Do not generate SIGPIPE
 MSG_MORE	nil	Sender will send more
+MSG_FASTOPEN nil Reduce step of the handshake process
 
 SOL_SOCKET	nil	Socket-level options
 SOL_IP	nil	IP socket options