diff --git a/docs/notebook_requirements.txt b/docs/notebook_requirements.txt
index fc5b1b29..010d9697 100644
--- a/docs/notebook_requirements.txt
+++ b/docs/notebook_requirements.txt
@@ -48,7 +48,7 @@ soupsieve==2.6
 terminado==0.18.1
 testpath==0.6.0
 tinycss2==1.2.1
-tornado==6.5.1
+tornado==6.5.7
 traitlets==5.14.3
 wcwidth==0.2.13
 webencodings==0.5.1