diff --git a/tox.ini b/tox.ini
index 15911b4c..d9db8990 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist=py25,py26,py27
+envlist=py25,py26,py27,pypy
 
 [testenv]
 commands=make test