diff --git a/tox.ini b/tox.ini
index bba0a64..5eb8b10 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,6 +16,7 @@
 commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
+basepython = python3
 commands =
   sh ./tools/misc-sanity-checks.sh
   flake8
@@ -23,9 +24,11 @@
   sh
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 setenv =
     {[testenv]setenv}
     PYTHON=coverage run --source neutron_tempest_plugin --parallel-mode
@@ -36,13 +39,16 @@
     coverage xml -o cover/coverage.xml
 
 [testenv:docs]
+basepython = python3
 commands = python setup.py build_sphinx
 
 [testenv:releasenotes]
+basepython = python3
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper -t neutron_tempest_plugin/ {posargs}
 
 [flake8]