diff --git a/tox.ini b/tox.ini
index 42a2619..1dfcac4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,6 +14,8 @@ commands =
 	yapf -dr sprockets_statsd tests setup.py docs/conf.py
 
 [testenv:distcheck]
+allowlist_externals =
+	rm
 deps =
 	twine
 	wheel
@@ -25,6 +27,7 @@ commands =
 	rm -fr {envtmpdir}/dist
 
 [testenv:tornado5]
+base_python = py39
 deps =
 	tornado>=5,<6
 	.[dev]