diff --git a/python/python-guestbook/src/backend/requirements.txt b/python/python-guestbook/src/backend/requirements.txt
index ab818773b..97f356811 100644
--- a/python/python-guestbook/src/backend/requirements.txt
+++ b/python/python-guestbook/src/backend/requirements.txt
@@ -1,4 +1,4 @@
-Flask==2.3.3
+Flask==3.1.3
 Flask-PyMongo==2.3.0
 bleach==5.0.1
 debugpy # Required for debugging