diff --git a/tox.ini b/tox.ini
index 18a6eea7..262d31cb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,9 +1,10 @@
 [tox]
 minversion = 1.6
-envlist = py27,py33,pep8
+envlist = docs,py37,pep8
 skipsdist = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} -U --force-reinstall {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
@@ -16,7 +17,7 @@ commands = python setup.py testr --testr-args='{posargs}'
 commands = flake8 {posargs}
 
 [testenv:cover]
-basepython = python2.7
+basepython = python3
 setenv =
   {[testenv]setenv}
   PYTHON=coverage run --source cloudbaseinit --parallel-mode