diff --git a/requirements/development.txt b/requirements/development.txt
index c16a092..22bf8ac 100644
--- a/requirements/development.txt
+++ b/requirements/development.txt
@@ -12,7 +12,7 @@ pyflakes==1.6.0
 mccabe==0.6.1
 pytest==3.4.0
 pytest-cov==2.5.1
-tox==2.9.1
+tox==3.1.3
 coveralls==1.2.0
 mock==2.0.0