diff --git a/tox.ini b/tox.ini
index 3f9f0943..78a9de40 100644
--- a/tox.ini
+++ b/tox.ini
@@ -17,19 +17,24 @@ deps =
 commands = python setup.py test --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+basepython = python3
 commands = flake8
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 commands = python setup.py test --coverage --coverage-package-name=toscaparser --testr-args='{posargs}'
 
 [testenv:docs]
+basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -b html doc/source doc/build/html
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper -t toscaparser/tests {posargs}
 
 [flake8]