diff --git a/requirements.txt b/requirements.txt
index d0c1602d..f5435958 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ flake8==3.7.6
 
 # Testing
 # ------------------------------------------------------------------------------
-tox==3.8.1
+tox==3.8.3
 pytest==4.3.1
 pytest-cookies==0.3.0
 pyyaml==5.1