diff --git a/tox.ini b/tox.ini
index 0d41f0395..01d12ee6e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist=py24,py25,py26,py27,py31,du07,du06,du05
+envlist=py24,py25,py26,py27,py31,pypy,du07,du06,du05
 
 [testenv]
 deps=nose
@@ -20,6 +20,11 @@ deps=
 [testenv:py31]
 deps=https://bitbucket.org/jpellerin/nose3/get/tip.zip
 
+[testenv:pypy]
+deps=
+    nose
+    simplejson
+
 [testenv:du05]
 deps=
     nose