diff --git a/requirements_dev.txt b/requirements_dev.txt
index 57273de..f88ce83 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,7 +3,7 @@ bumpversion==0.5.3
 wheel==0.34.2
 watchdog==0.9.0
 flake8==3.7.9
-tox==3.14.6
+tox==3.15.0
 coverage==5.0.4
 Sphinx==3.0.3
 cryptography==2.8