diff --git a/requirements_dev.txt b/requirements_dev.txt
index 23f65b9..abd9440 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -31,7 +31,7 @@ six==1.10.0
 slackclient==1.0.1
 snowballstemmer==1.2.1
 Sphinx==1.4.4
-tox==2.3.1
+tox==4.23.2
 Unidecode==0.4.19
 virtualenv==15.0.2
 watchdog==0.8.3