diff --git a/tox.ini b/tox.ini
index 860a0a35..41e68263 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,19 +20,23 @@ deps = -r{toxinidir}/requirements.txt
 commands = stestr run {posargs}
 
 [testenv:pep8]
+basepython = python3
 commands =
   flake8
   bandit -r keystonemiddleware -x tests -n5
 
 [testenv:bandit]
+basepython = python3
 # NOTE(browne): This is required for the integration test job of the bandit
 # project. Please do not remove.
 commands = bandit -r keystonemiddleware -x tests -n5
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 setenv =
     {[testenv]setenv}
     PYTHON=coverage run --source keystonemiddleware --parallel-mode
@@ -43,6 +47,7 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:debug]
+basepython = python3
 
 commands = oslo_debug_helper -t keystonemiddleware/tests {posargs}
 
@@ -58,12 +63,14 @@ show-source = True
 exclude = .venv,.tox,dist,doc,*egg,build
 
 [testenv:docs]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands=
     doc8 doc/source
     python setup.py build_sphinx
 
 [testenv:releasenotes]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html