diff --git a/tox.ini b/tox.ini
index 925577c..835b4ac 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,6 +5,7 @@
 setenv = VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
+basepython = python3
 
 [testenv:pep8]
 commands = flake8