diff --git a/requirements-optional.txt b/requirements-optional.txt
index 27fe558..011a18d 100644
--- a/requirements-optional.txt
+++ b/requirements-optional.txt
@@ -1,4 +1,4 @@
 Flask==0.9
 Twisted==10.2.0
 bottle==0.11.6
-tornado==2.2.1
+tornado==6.3.2