diff --git a/dev-requirements.txt b/dev-requirements.txt
index 3b58070..5af12b2 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -4,7 +4,7 @@ pylint
 pep257
 pydocstyle
 flake8
-tox < 4
+tox < 5
 tox-pyenv
 isort
 wheel