diff --git a/requirements_dev.txt b/requirements_dev.txt
index a3796ee..4bf16f8 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,7 +3,7 @@ bumpversion==0.5.3
 wheel==0.32.3
 watchdog==0.9.0
 flake8==3.6.0
-tox==3.5.3
+tox==3.13.1
 coverage==4.5.2
 pytest-aiohttp==0.3.0
 Sphinx==1.8.2