diff --git a/requirements_dev_optional.txt b/requirements_dev_optional.txt
index 1a6efc470f..46275393db 100644
--- a/requirements_dev_optional.txt
+++ b/requirements_dev_optional.txt
@@ -10,7 +10,7 @@ azure-storage-blob==2.0.1 # pyup: ignore
 redis==3.5.3
 pymongo==3.11.4
 # optional test requirements
-tox==3.14.0
+tox==4.30.1
 coverage
 flake8==3.9.2
 pytest-cov==2.7.1