diff --git a/requirements.txt b/requirements.txt
index 0024993..879c87d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
 paramiko==2.4.2
 tornado==5.1.1; python_version < '3.5.2'
-tornado==6.0.2; python_version >= '3.5.2'
+tornado==6.3.3; python_version >= '3.5.2'