diff --git a/ChangeLog b/ChangeLog
index 90d0d27d9f..f9165021c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Dec 26 10:49:14 2013  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* version.h (RUBY_VERSION): 2.2.0 development has started.
+
 Thu Dec 26 10:27:53 2013  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* tool/merger.rb (tag): support 2.1.1 semi-automatic tagging and 2.2.0
diff --git a/version.h b/version.h
index 33f32caeda..defd983ea9 100644
--- a/version.h
+++ b/version.h
@@ -1,4 +1,4 @@
-#define RUBY_VERSION "2.1.0"
+#define RUBY_VERSION "2.2.0"
 #define RUBY_RELEASE_DATE "2013-12-26"
 #define RUBY_PATCHLEVEL -1
 #define RUBY_BRANCH_NAME "trunk"