diff --git a/requirements.txt b/requirements.txt
index b4cbf4d..375dcab 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,4 +6,4 @@ pytest==4.4.1
 pytest-cov==2.6.1
 pytest-django==3.4.8
 sphinx_rtd_theme==0.4.3
-tox==3.8.6
+tox==3.9.0