diff --git a/tox.ini b/tox.ini
index 4aad012cd..0b2aa78f5 100644
--- a/tox.ini
+++ b/tox.ini
@@ -24,6 +24,7 @@ commands =
   {toxinidir}/tools/fast8.sh
 
 [testenv:pep8]
+basepython = python3
 commands =
     flake8
     bandit -r openstackclient -x tests -s B105,B106,B107,B401,B404,B603,B606,B607,B110,B605,B101
@@ -87,6 +88,7 @@ commands =
     {toxinidir}/openstackclient/tests/functional/run_stestr.sh {posargs}
 
 [testenv:venv]
+basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/requirements.txt
@@ -94,6 +96,7 @@ deps =
 commands = {posargs}
 
 [testenv:cover]
+basepython = python3
 setenv =
     VIRTUAL_ENV={envdir}
     PYTHON=coverage run --source openstackclient --parallel-mode
@@ -109,6 +112,7 @@ commands =
     oslo_debug_helper -t openstackclient/tests {posargs}
 
 [testenv:docs]
+basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/requirements.txt
@@ -118,6 +122,7 @@ commands =
   sphinx-build -a -E -W -d doc/build/doctrees -b man doc/source doc/build/man
 
 [testenv:releasenotes]
+basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/doc/requirements.txt