diff --git a/requirements_dev.txt b/requirements_dev.txt
index 4a52b4b..24eed24 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,7 +3,7 @@ bumpversion==0.5.3
 wheel==0.29.0
 watchdog==0.8.3
 flake8==2.6.0
-tox==2.3.1
+tox==3.14.3
 coverage==4.1
 Sphinx==1.4.8
 coveralls==1.2.0