diff --git a/tox.ini b/tox.ini
index 85a4573..f9ba126 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py26, py27, pypy, py32
+envlist = py26, py27, pypy, py32, py33
 
 [testenv]
 commands =