diff --git a/requirements.txt b/requirements.txt
index f9369cd..42e0314 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -54,7 +54,7 @@ Send2Trash==1.5.0
 six==1.12.0
 terminado==0.8.2
 testpath==0.4.2
-tornado==6.3.2
+tornado==6.3.3
 traitlets==4.3.2
 traits==5.1.1
 traitsui==6.0.0