diff --git a/tox.ini b/tox.ini
index 8421c163..d341908b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27, py33, py34, py35, py36
+envlist = py27, py33, py34, py35, py36, py36-env27, py36-env33, py36-env34, py36-env35
 [testenv]
 deps =
     pytest>=2.3.5, < 3.3