diff --git a/requirements_dev.txt b/requirements_dev.txt
index afb028c..afd36d3 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,7 +3,7 @@ bumpversion==0.5.3
 flake8==3.7.8
 wheel==0.33.6
 coverage==4.5.4
-tox==3.14.0
+tox==4.23.0
 pytest-runner==5.1
 Sphinx==2.2.0
 pytest==5.2.1