diff --git a/requirements.txt b/requirements.txt
index dddcfc8..4f37081 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -52,7 +52,7 @@ Send2Trash==1.5.0
 six==1.11.0
 terminado==0.8.1
 testpath==0.4.2
-tornado==5.1.1
+tornado==6.3.3
 traitlets==4.3.2
 urllib3==1.24.2
 wcwidth==0.1.7