diff --git a/requirements.txt b/requirements.txt
index 04e43f1..8a0f76f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-tornado==6.0.4
+tornado==6.3.3
 isodate==0.6.0
 pytest==5.4.1
 schwifty==2020.11.0