diff --git a/ch14/requirements/dev.txt b/ch14/requirements/dev.txt
index ca6e243..fd12d7e 100644
--- a/ch14/requirements/dev.txt
+++ b/ch14/requirements/dev.txt
@@ -257,7 +257,7 @@ terminado==0.18.1
     #   jupyter-server-terminals
 tinycss2==1.4.0
     # via bleach
-tornado==6.5.7
+tornado==6.5.8
     # via
     #   ipykernel
     #   jupyter-client