diff --git a/Chapter09/Ch9/server/requirements.txt b/Chapter09/Ch9/server/requirements.txt
index 0ae6787..c54e72b 100644
--- a/Chapter09/Ch9/server/requirements.txt
+++ b/Chapter09/Ch9/server/requirements.txt
@@ -12,4 +12,4 @@ python-dateutil==2.7.0
 requests==2.18.4
 six==1.11.0
 urllib3==1.22
-Werkzeug==0.14.1
+Werkzeug==0.15.3