diff --git a/tox.ini b/tox.ini
index e890eba..3a54356 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,6 +4,7 @@ envlist = docs,pep8
 skipsdist = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 setenv = VIRTUAL_ENV={envdir}
 install_command = pip install {opts} {packages}