diff --git a/tox.ini b/tox.ini
index 0544c3f..73dec7e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,6 +16,7 @@ commands = ostestr {posargs}
 passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
 [testenv:cover]
+basepython = python3
 commands = {toxinidir}/tools/cover.sh {posargs}
 
 [testenv:debug-py27]
@@ -27,6 +28,7 @@ basepython = python3.5
 commands = oslo_debug_helper -t sahara/tests/unit {posargs}
 
 [testenv:pep8]
+basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/requirements.txt
@@ -42,9 +44,11 @@ commands =
     bandit -c bandit.yaml -r sahara -n5 -p sahara_default -x tests
 
 [testenv:genpolicy]
+basepython = python3
 commands = oslopolicy-sample-generator --config-file tools/config/sahara-policy-generator.conf
 
 [testenv:venv]
+basepython = python3
 commands = {posargs}
 
 [testenv:images]
@@ -52,6 +56,7 @@ sitepackages = True
 commands = {posargs}
 
 [testenv:docs]
+basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/doc/requirements.txt
@@ -65,6 +70,7 @@ commands =
 whitelist_externals = rm
 
 [testenv:api-ref]
+basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/doc/requirements.txt
@@ -76,15 +82,18 @@ whitelist_externals = rm
 
 
 [testenv:pylint]
+basepython = python3
 setenv = VIRTUAL_ENV={envdir}
 commands = bash tools/lintstack.sh
 
 [testenv:genconfig]
+basepython = python3
 commands =
     oslo-config-generator --config-file tools/config/config-generator.sahara.conf \
     --output-file etc/sahara/sahara.conf.sample
 
 [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
@@ -94,6 +103,7 @@ commands =
 whitelist_externals = rm
 
 [testenv:debug]
+basepython = python3
 # It runs tests from the specified dir (default is sahara/tests)
 # in interactive mode, so, you could use pbr for tests debug.
 # Example usage: tox -e debug -- -t sahara/tests/unit some.test.path
@@ -101,6 +111,7 @@ whitelist_externals = rm
 commands = oslo_debug_helper -t sahara/tests/unit {posargs}
 
 [testenv:bandit]
+basepython = python3
 deps = -r{toxinidir}/test-requirements-bandit.txt
 commands = bandit -c bandit.yaml -r sahara -n5 -p sahara_default -x tests
 
@@ -120,6 +131,7 @@ import_exceptions = sahara.i18n
 local-check-factory = sahara.utils.hacking.checks.factory
 
 [testenv:bindep]
+basepython = python3
 # Do not install any requirements. We want this to be fast and work even if
 # system dependencies are missing, since it's used to tell you what system
 # dependencies are missing! This also means that bindep must be installed