diff --git a/tox.ini b/tox.ini
index c8d8071c..d42396bc 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,6 +4,7 @@ minversion = 1.6
 skipsdist = True
 
 [testenv]
+basepython = python2
 install_command = pip install -U {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/test-requirements.txt