diff --git a/CHANGES.rst b/CHANGES.rst
index c43b419..b7d1664 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,5 +1,11 @@
 Changes
 ~~~~~~~
+ 
+0.5 (unreleased)
+----------------
+
+- ...
+
 
 0.4 (2015-02-26)
 ----------------
diff --git a/setup.py b/setup.py
index e0e4efa..5607df0 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@
 import sys
 from setuptools import setup, find_packages
 
-version = '0.4'
+version = '0.5dev'
 
 if sys.version_info < (2, 6):
     sys.stderr.write("This package requires Python 2.6 or newer. "