diff --git a/requirements.txt b/requirements.txt
index 6eb48a1..18f3f8a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ bump2version==1.0.0
 wheel==0.34.2
 watchdog==0.10.3
 flake8==3.8.3
-tox==3.18.0
+tox==4.23.2
 coverage==5.2.1
 Sphinx==3.1.2
 twine==3.2.0
diff --git a/requirements_dev.txt b/requirements_dev.txt
index d3eacc3..f99b36d 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,7 +3,7 @@ bump2version==1.0.0
 wheel==0.34.2
 watchdog==0.10.3
 flake8==3.8.3
-tox==3.18.0
+tox==4.23.2
 coverage==5.2.1
 Sphinx==3.1.2
 twine==3.2.0