diff --git a/tox.ini b/tox.ini
index 5d8f70e..e7f04c4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -47,23 +47,27 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:debug]
+basepython = python3
 description = Allows to run unit-test with debug mode enabled
 commands =
   {[testenv]commands}
   oslo_debug_helper -t {env:OS_TEST_PATH} {posargs}
 
 [testenv:bashate]
+basepython = python3
 description = Validates (pep8-like) devstack plugins
 skip_install = True
 usedevelop = False
 commands = bash {toxinidir}/tools/bashate.sh
 
 [testenv:bandit]
+basepython = python3
 skip_install = True
 usedevelop = False
 commands = bandit -r monasca_events_api -n5 -x monasca_events_api/tests
 
 [testenv:flake8]
+basepython = python3
 skip_install = True
 usedevelop = False
 commands =
@@ -87,6 +91,7 @@ commands =
   {[testenv:releasenotes]commands}
 
 [testenv:api-ref]
+basepython = python3
 description = Called from CI scripts to test and publish the API Ref
 commands =
   rm -rf api-ref/build
@@ -101,6 +106,7 @@ commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:devdocs]
+basepython = python3
 description = Builds developer documentation
 commands =
   {[testenv]commands}
@@ -110,6 +116,7 @@ commands =
   python setup.py build_sphinx
 
 [testenv:checkniceness]
+basepython = python3
 description = Validates (pep-like) documentation
 skip_install = True
 usedevelop = False
@@ -119,6 +126,7 @@ commands =
   doc8 --file-encoding utf-8 {toxinidir}/releasenotes
 
 [testenv:checkjson]
+basepython = python3
 description = Validates all json samples inside doc folder
 deps =
 whitelist_externals =
@@ -129,10 +137,12 @@ commands =
   bash -c '! find doc/ -type f -name *.json | xargs -t -n1 python -m json.tool 2>&1 > /dev/null | grep -B1 -v ^python'
 
 [testenv:genconfig]
+basepython = python3
 description = Generates sample documentation file for monasca-events-api
 commands = oslo-config-generator --config-file=config-generator/config.conf
 
 [testenv:genpolicy]
+basepython = python3
 description = Generates sample policy.yaml file for monasca-events-api
 commands = oslopolicy-sample-generator --config-file=config-generator/policy.conf