diff --git a/appengine/flexible/extending_runtime/requirements.txt b/appengine/flexible/extending_runtime/requirements.txt
index 573d9bfa6d3..d0b9324ee93 100644
--- a/appengine/flexible/extending_runtime/requirements.txt
+++ b/appengine/flexible/extending_runtime/requirements.txt
@@ -1,2 +1,2 @@
 Flask==1.1.1
-gunicorn==20.0.4
+gunicorn==22.0.0