diff --git a/setup.py b/setup.py
index 35d62446..d3849f0d 100644
--- a/setup.py
+++ b/setup.py
@@ -25,7 +25,7 @@ except ImportError:
 
 kwargs = {}
 
-version = "3.0.1"
+version = "3.1.dev2"
 
 with open('README.rst') as f:
     long_description = f.read()
diff --git a/tornado/__init__.py b/tornado/__init__.py
index c188a1b5..68434e18 100644
--- a/tornado/__init__.py
+++ b/tornado/__init__.py
@@ -25,5 +25,5 @@ from __future__ import absolute_import, division, print_function, with_statement
 # is zero for an official release, positive for a development branch,
 # or negative for a release candidate or beta (after the base version
 # number has been incremented)
-version = "3.0.1"
-version_info = (3, 0, 1, 0)
+version = "3.1.dev2"
+version_info = (3, 1, 0, -99)