diff --git a/appengine/websockets/package.json b/appengine/websockets/package.json
index e1831711d0..edc02f4c9e 100644
--- a/appengine/websockets/package.json
+++ b/appengine/websockets/package.json
@@ -19,7 +19,7 @@
   "dependencies": {
     "express": "4.15.4",
     "pug": "2.0.3",
-    "socket.io": "2.2.0"
+    "socket.io": "3.0.0"
   },
   "devDependencies": {
     "@google-cloud/nodejs-repo-tools": "3.1.0",