diff --git a/tox.ini b/tox.ini
index a1e27a3d..a0b04077 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 envlist = py3,pep8
-minversion = 3.1.1
+minversion = 3.18.0
 ignore_basepython_conflict = True
 
 [testenv]
@@ -26,7 +26,7 @@ commands =
     rm -f .testrepository/times.dbm
     find . -type f -name "*.pyc" -delete
     stestr run --concurrency 1 --slowest {posargs}
-Allowlist_externals =
+allowlist_externals =
   find
   rm
 [testenv:cover]