diff --git a/tox.ini b/tox.ini
index 8d33520..19e01ce 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,6 +4,7 @@ skipsdist = True
 envlist = py35,py27,pep8
 
 [testenv]
+basepython = python3
 setenv = VIRTUAL_ENV={envdir}
          LANG=en_US.UTF-8
          LANGUAGE=en_US:en
@@ -16,6 +17,9 @@ usedevelop = True
 commands = python setup.py testr --slowest --testr-args='{posargs}'
 distribute = false
 
+[testenv:py27]
+basepython = python2.7
+
 [testenv:functional]
 basepython = python2.7
 setenv = {[testenv]setenv}