diff --git a/setup.py b/setup.py
index dca062d5..b544df67 100644
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,7 @@ if "linux" in sys.platform.lower() and not python_26:
     extensions.append(distutils.core.Extension(
         "tornado.epoll", ["tornado/epoll.c"]))
 
-version = "2.2.post1"
+version = "2.3.rc1"
 
 if major >= 3:
     import setuptools  # setuptools is required for use_2to3
diff --git a/tornado/__init__.py b/tornado/__init__.py
index 1ea27266..05e10780 100644
--- a/tornado/__init__.py
+++ b/tornado/__init__.py
@@ -25,5 +25,5 @@ from __future__ import absolute_import, division, with_statement
 # is zero for an official release, positive for a development branch,
 # or negative for a release candidate (after the base version number
 # has been incremented)
-version = "2.2.post1"
-version_info = (2, 2, 0, 1)
+version = "2.3.rc1"
+version_info = (2, 3, 0, -1)