diff --git a/requirements.txt b/requirements.txt
index 5e2e27f5..c870c953 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,7 +9,7 @@ flake8==3.7.7
 
 # Testing
 # ------------------------------------------------------------------------------
-tox==3.12.1
+tox==3.13.1
 pytest==4.6.3
 pytest_cases==1.9.1
 pytest-cookies==0.3.0