diff --git a/tox.ini b/tox.ini
index 65f5720e9..625324909 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,32 +18,39 @@ commands =
 whitelist_externals = find
 
 [testenv:integration]
+basepython = python3
 setenv = {[testenv]setenv}
          ZAQAR_TEST_INTEGRATION=1
          OS_TEST_PATH=./zaqar/tests/functional
 commands = ostestr --concurrency 1 {posargs}
 
 [testenv:pep8]
+basepython = python3
 commands = flake8
 
 [testenv:genconfig]
+basepython = python3
 commands =
   oslo-config-generator --config-file etc/oslo-config-generator/zaqar.conf
 
 [testenv:genpolicy]
+basepython = python3
 commands =
   oslopolicy-sample-generator --config-file etc/zaqar-policy-generator.conf
 
 [testenv:cover]
+basepython = python3
 commands =
   python setup.py testr --coverage \
     --testr-args='^(?!.*test.*coverage).*$'
   coverage report
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 deps =
   -r{toxinidir}/doc/requirements.txt
   -r{toxinidir}/test-requirements.txt
@@ -53,6 +60,7 @@ commands =
   sphinx-build -W -b html api-ref/source api-ref/build/html
 
 [testenv:api-ref]
+basepython = python3
 # This environment is called from CI scripts to test and publish
 # the API Ref to developer.openstack.org.
 #
@@ -63,9 +71,11 @@ commands =
   sphinx-build -W -b html -d api-ref/build/doctrees api-ref/source api-ref/build/html
 
 [testenv:debug]
+basepython = python3
 commands = oslo_debug_helper {posargs}
 
 [testenv:releasenotes]
+basepython = python3
 commands =
   doc8 releasenotes/source releasenotes/notes
   sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html