diff --git a/requirements.txt b/requirements.txt
index b216813..57ba269 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -49,7 +49,7 @@ six==1.12.0
 terminado==0.8.1
 testpath==0.4.2
 toolz==0.9.0
-tornado==5.1.1
+tornado==6.4.1
 tqdm==4.30.0
 traitlets==4.3.2
 typed-ast==1.3.0