diff --git a/Ch9/server/requirements.txt b/Ch9/server/requirements.txt
index 695e16f..0faef7f 100644
--- a/Ch9/server/requirements.txt
+++ b/Ch9/server/requirements.txt
@@ -5,7 +5,7 @@ click==6.7
 Flask==1.0
 idna==2.6
 itsdangerous==0.24
-Jinja2==2.10
+Jinja2==2.11.3
 MarkupSafe==1.0
 Pillow==5.0.0
 python-dateutil==2.7.0