diff --git a/tox.ini b/tox.ini
index 9b0f71038..3aa6a6d43 100644
--- a/tox.ini
+++ b/tox.ini
@@ -258,7 +258,8 @@ commands=
     pyinstaller -y --clean pyinstaller.spec
 
 [testenv:tarballs]
+basepython = python3
 deps =
 commands =
          python setup.py update_version
-         python setup.py sdist --formats=bztar,gztar,zip bdist_wheel
+         python setup.py sdist --formats=bztar,gztar,zip bdist_wheel --universal