diff --git a/requirements.txt b/requirements.txt
index 97b4e227..46f735cd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -50,7 +50,7 @@ six==1.11.0
 snowballstemmer==1.2.1
 Sphinx==1.7.4
 sphinxcontrib-websupport==1.1.0
-tox==3.0.0
+tox==4.23.2
 typing==3.6.4
 urllib3==1.22
 virtualenv==16.0.0
diff --git a/requirements_dev.txt b/requirements_dev.txt
index 5404d8d3..4b6ffa52 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -48,7 +48,7 @@ six==1.11.0
 snowballstemmer==1.2.1
 Sphinx==1.7.4
 sphinxcontrib-websupport==1.1.0
-tox==3.0.0
+tox==4.23.2
 typing==3.6.4
 urllib3==1.22
 virtualenv==16.0.0