diff --git a/src/index.ts b/src/index.ts
index 170054d..b7fd3fe 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -26,7 +26,7 @@ async function main() {
 
   const { url } = await startStandaloneServer(server, {
     listen: {
-      port: 4000,
+      port: process.env.PORT ? parseInt(process.env.PORT) : 4000,
     },
     context: async ({ req, res }) => {
       return {