diff --git a/requirements.txt b/requirements.txt
index 0e8a622..83eaf56 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -133,7 +133,7 @@ soupsieve==2.2.1
     # via beautifulsoup4
 testpath==0.4.4
     # via nbconvert
-tornado==6.1
+tornado==6.3.3
     # via jupyter-client
 traitlets==5.0.5
     # via