diff --git a/optional-kubernetes-engine/requirements.txt b/optional-kubernetes-engine/requirements.txt
index 33ba8279..d307d345 100644
--- a/optional-kubernetes-engine/requirements.txt
+++ b/optional-kubernetes-engine/requirements.txt
@@ -1,4 +1,4 @@
-Flask==1.0.4
+Flask==3.1.3
 google-cloud-datastore==1.7.1
 google-cloud-storage==1.23.0
 google-cloud-logging==1.8.0