diff --git a/tox.ini b/tox.ini
index 054cd511..9bf7b85d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -48,6 +48,9 @@ norecursedirs  = .tox .venv
 [testenv:venv]
 commands = {posargs}
 
+[testenv:py39]
+basepython = python3.9
+
 [testenv:py38]
 basepython = python3.8