diff --git a/dev-requirements.txt b/dev-requirements.txt
index 1cadab3..de8288a 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -3,7 +3,7 @@ invoke==1.0.0
 
 # Testing
 pytest==3.6.2
-tox==3.0.0
+tox==3.1.1
 
 # Syntax checking
 flake8==3.5.0