diff --git a/tox.ini b/tox.ini
index 3d1c6f0c7..a6be3a377 100644
--- a/tox.ini
+++ b/tox.ini
@@ -32,16 +32,19 @@ commands =
   coverage report
 
 [testenv:debug]
+basepython = python3
 commands =
   oslo_debug_helper -t ./monasca_api/tests {posargs}
 
 [testenv:flake8]
+basepython = python3
 skip_install = True
 usedevelop = False
 commands =
   flake8 monasca_api
 
 [testenv:bandit]
+basepython = python3
 skip_install = True
 usedevelop = False
 commands =
@@ -49,11 +52,13 @@ commands =
   bandit -r monasca_api -n5 -s B101 -x monasca_api/tests
 
 [testenv:bashate]
+basepython = python3
 skip_install = True
 usedevelop = False
 commands = bash {toxinidir}/tools/bashate.sh
 
 [testenv:pep8]
+basepython = python3
 commands =
   {[testenv:flake8]commands}
   {[testenv:bandit]commands}
@@ -61,6 +66,7 @@ commands =
   {[testenv:checkniceness]commands}
 
 [testenv:docs]
+basepython = python3
 description = Builds api-ref, api-guide, releasenotes and devdocs
 commands =
   {[testenv:devdocs]commands}
@@ -68,6 +74,7 @@ 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
@@ -76,6 +83,7 @@ commands =
     api-ref/source api-ref/build/html
 
 [testenv:releasenotes]
+basepython = python3
 description = Called from CI script to test and publish the Release Notes
 commands =
   rm -rf releasenotes/build
@@ -83,6 +91,7 @@ commands =
     releasenotes/source releasenotes/build/html
 
 [testenv:devdocs]
+basepython = python3
 description = Builds developer documentation
 commands =
   rm -rf doc/build doc/source/contributor/api
@@ -90,6 +99,7 @@ commands =
   python setup.py build_sphinx
 
 [testenv:checkniceness]
+basepython = python3
 skip_install = True
 usedevelop = False
 description = Validates (pep-like) documenation
@@ -101,6 +111,7 @@ commands =
   doc8 --file-encoding utf-8 {toxinidir}/releasenotes
 
 [testenv:checkjson]
+basepython = python3
 description = Validates all json samples inside doc folder
 deps =
 skip_install = True
@@ -114,13 +125,16 @@ commands =
     xargs -t -n1 python -m json.tool 2>&1 > /dev/null | grep -B1 -v ^python'
 
 [testenv:genconfig]
+basepython = python3
 description = Generates sample configuration file for monasca-api
 commands = oslo-config-generator --config-file=config-generator/api-config.conf
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:bindep]
+basepython = python3
 deps = bindep
 commands = bindep test