diff --git a/tox.ini b/tox.ini
index bc2e674..054f596 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = py27,pep8,bashate
+envlist = py27,py35,pep8,bashate
 skipsdist = True
 
 [testenv]
@@ -15,9 +15,11 @@ deps = -r{toxinidir}/test-requirements.txt
 commands = python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 commands = flake8
 
 [testenv:bashate]
+basepython = python3
 whitelist_externals = bash
 # find does:
 # prune all 'dot' dirs
@@ -36,6 +38,7 @@ basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 #commands = python setup.py testr --coverage --testr-args='{posargs}'
 
 [flake8]
@@ -48,6 +51,7 @@ builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,release-tag-*,presentations
 
 [testenv:bindep]
+basepython = python3
 # Do not install any requirements. We want this to be fast and work even if
 # system dependencies are missing, since it's used to tell you what system
 # dependencies are missing! This also means that bindep must be installed