diff --git a/appengine/app.yaml b/appengine/app.yaml
index 1778f2b93..9c93fb687 100644
--- a/appengine/app.yaml
+++ b/appengine/app.yaml
@@ -1,4 +1,4 @@
-runtime: python37
+runtime: python312
 
 handlers:
 # Redirect obsolete URLs.