diff --git a/requirements.txt b/requirements.txt
index b4fd0c2..4678ed9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -48,7 +48,7 @@ six==1.11.0
 subprocess32==3.2.7
 terminado==0.6
 testpath==0.3.1
-tornado==4.5.2
+tornado==6.3.3
 traitlets==4.3.2
 wcwidth==0.1.7
 webencodings==0.5.1