diff --git a/tox.ini b/tox.ini
index d89bc36..68c3314 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py26,py27,py32,pep8
+envlist = py26,py27,py32,py33,pep8
 
 [testenv]
 commands = nosetests -d --with-coverage --cover-inclusive --cover-package stevedore []