diff --git a/tox.ini b/tox.ini
index 0c74d73e74..247e3f2555 100644
--- a/tox.ini
+++ b/tox.ini
@@ -82,6 +82,7 @@ commands=
 
 # thanks to https://julien.danjou.info/the-best-flake8-extensions/
 [testenv:pep8]
+basepython = python3.7
 deps=
       flake8
       flake8-import-order