diff --git a/tox.ini b/tox.ini
index dc0388ccd..de61fdbdf 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,7 +10,12 @@ envlist =
 
 [testenv]
 basepython =
-             py35: python3.5
+            py26: python2.6
+            py27: python2.7
+            py32: python3.2
+            py33: python3.3
+            py34: python3.4
+            py35: python3.5
 
 
 commands = ./runtests.py --fast {posargs} --coverage