diff --git a/tox.ini b/tox.ini
index c381b45..6f3cade 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,20 +16,25 @@ commands = rm -f .testrepository/times.dbm
            python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 commands = flake8
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 commands =
    python setup.py testr --coverage --testr-args='{posargs}'
    coverage report
 
 [testenv:docs]
+basepython = python3
 commands = python setup.py build_sphinx
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper -t watcherclient/tests/unit {posargs}
 
 [testenv:functional]
@@ -56,6 +61,7 @@ builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 
 [testenv:wheel]
+basepython = python3
 commands = python setup.py bdist_wheel
 
 [hacking]