diff --git a/tox.ini b/tox.ini
index 80d175dfed..0cbd765bd1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -17,6 +17,7 @@ commands = ostestr {posargs}
 passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 
 [testenv:unit-with-driver-libs]
+basepython = python2
 deps = {[testenv]deps}
     -r{toxinidir}/driver-requirements.txt