diff --git a/tox.ini b/tox.ini
index 8ced886b8..bcbeeeddf 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.0
-envlist = mypy, py3{6,7,8}-cov, htmlcov
+envlist = mypy, py3{6,7,8,9}-cov, htmlcov
 skip_missing_interpreters=true
 
 [testenv]