diff --git a/messages/Dockerfile b/messages/Dockerfile
index 1d35d27..10cb2a0 100644
--- a/messages/Dockerfile
+++ b/messages/Dockerfile
@@ -1,5 +1,6 @@
 FROM oven/bun:1 AS base
 WORKDIR /usr/src/app
+ENV APP_PORT 3000
 
 # install dependencies into temp directory
 # this will cache them and speed up future builds
@@ -21,5 +22,5 @@ COPY --from=prerelease /usr/src/app/package.json .
 
 # run the app
 USER bun
-EXPOSE 3000/tcp
+EXPOSE $APP_PORT/tcp
 ENTRYPOINT [ "bun", "run", "app.js" ]
diff --git a/messages/src/app.js b/messages/src/app.js
index 31a5a15..896176d 100644
--- a/messages/src/app.js
+++ b/messages/src/app.js
@@ -10,6 +10,7 @@ const { indexRouter } = require("./routes/indexRouter");
 const { authRouter } = require("./routes/authRouter");
 
 const app = express();
+const port = process.env.APP_PORT || 5173;
 
 const assetsPath = path.join(path.dirname(__dirname), "public");
 app.use(express.static(assetsPath));
@@ -38,7 +39,9 @@ app.use((req, res, next) => {
 app.use("/", indexRouter);
 app.use("/auth", authRouter);
 
-const server = app.listen(5173, () => console.log(`App running on port: 5173`));
+const server = app.listen(port, () =>
+  console.log(`App running on port: ${port}`),
+);
 
 const gracefulShutdownHandler = (signal) => {
   console.log(`\n${signal} received.`);