diff --git a/tox.ini b/tox.ini
index 13ac780..4b2822d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,6 +5,7 @@ skipsdist = True
 
 [testenv]
 usedevelop = True
+basepython = python3
 install_command = pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}