diff --git a/requirements.txt b/requirements.txt
index bb83ef94..f18b1205 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 pip==19.0.1
 wheel==0.32.3
 watchdog==0.9.0
-tox==3.7.0
+tox==3.24.0
 Sphinx==1.8.3
 twine==1.12.1
 cryptography==2.5