diff --git a/requirements.txt b/requirements.txt
index fbcf7e1..b0e70e6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
 pyjwt==1.7.1
 pypandoc==1.5 # only for converting README.md
-tornado==6.0.4
+tornado==6.3.3