diff --git a/tox.ini b/tox.ini
index 9a6d7ce1..980b432e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,18 +8,21 @@ envlist =
     black
     mypy
 
-[testenv]
-basepython = python3.9
-commands = python -m unittest
-
 [testenv:py36]
 basepython = python3.6
+commands = python -m unittest
 
 [testenv:py37]
 basepython = python3.7
+commands = python -m unittest
 
 [testenv:py38]
 basepython = python3.8
+commands = python -m unittest
+
+[testenv:py39]
+basepython = python3.9
+commands = python -m unittest
 
 [testenv:flake8]
 deps = flake8