diff --git a/appengine/cloudsql_postgresql/package.json b/appengine/cloudsql_postgresql/package.json
index 296ee7fbf2..38160b4a30 100644
--- a/appengine/cloudsql_postgresql/package.json
+++ b/appengine/cloudsql_postgresql/package.json
@@ -26,7 +26,7 @@
   },
   "dependencies": {
     "async": "2.5.0",
-    "express": "4.15.4",
+    "express": "4.21.0",
     "knex": "0.13.0",
     "pg": "7.3.0",
     "prompt": "1.0.0"