diff --git a/examples/zoo_app/requirements.txt b/examples/zoo_app/requirements.txt
index 4176fd55..bfe4a0b2 100644
--- a/examples/zoo_app/requirements.txt
+++ b/examples/zoo_app/requirements.txt
@@ -1,7 +1,7 @@
 aniso8601==9.0.1
 attrs==21.2.0
 click==7.1.2
-Flask==1.1.4
+Flask==2.3.2
 flask-restx==0.5.1
 itsdangerous==1.1.0
 Jinja2==2.11.3