diff --git a/requirements.txt b/requirements.txt
index f6b4544..86b292d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ sklearn==0.0
 ta==0.5.22
 TA-Lib==0.4.17
 tabulate==0.8.3
-tox==3.13.2
+tox==3.21.0
 pylint==2.3.1
 pyre-check==0.0.39
 pytest==4.6.3