diff --git a/src/cli.ts b/src/cli.ts
index c83a081..12c79b2 100755
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -21,7 +21,9 @@ prog.command('dev')
 
 prog.command('build [dest]')
 	.describe('Create a production-ready version of your app')
-	.action(async (dest = 'build') => {
+	.option('-p, --port', 'Default of process.env.PORT', '3000')
+	.example(`build custom-dir -p 4567`)
+	.action(async (dest = 'build', opts: { port: string }) => {
 		console.log(`> Building...`);
 
 		process.env.NODE_ENV = process.env.NODE_ENV || 'production';
@@ -32,7 +34,20 @@ prog.command('build [dest]')
 		try {
 			const { build } = await import('./cli/build');
 			await build();
-			console.error(`\n> Finished in ${elapsed(start)}. Type ${clorox.bold.cyan(dest === 'build' ? 'npx sapper start' : `npx sapper start ${dest}`)} to run the app.`);
+
+			const launcher = path.resolve(dest, 'index.js');
+
+			fs.writeFileSync(launcher, `
+				// generated by sapper build at ${new Date().toISOString()}
+				process.env.NODE_ENV = process.env.NODE_ENV || 'production';
+				process.env.SAPPER_DEST = __dirname;
+				process.env.PORT = process.env.PORT || ${opts.port || 3000};
+
+				console.log('Starting server on port ' + process.env.PORT);
+				require('./server.js');
+			`.replace(/^\t+/gm, '').trim());
+
+			console.error(`\n> Finished in ${elapsed(start)}. Type ${clorox.bold.cyan(`node ${dest}`)} to run the app.`);
 		} catch (err) {
 			console.error(err ? err.details || err.stack || err.message || err : 'Unknown error');
 		}
diff --git a/test/common/test.js b/test/common/test.js
index db18be2..5e667dd 100644
--- a/test/common/test.js
+++ b/test/common/test.js
@@ -1,3 +1,4 @@
+const fs = require('fs');
 const path = require('path');
 const assert = require('assert');
 const Nightmare = require('nightmare');
@@ -38,6 +39,7 @@ describe('sapper', function() {
 	rimraf.sync('export');
 	rimraf.sync('build');
 	rimraf.sync('.sapper');
+	rimraf.sync('start.js');
 
 	this.timeout(process.env.CI ? 30000 : 10000);
 
@@ -148,7 +150,7 @@ function run({ mode, basepath = '' }) {
 
 		before(() => {
 			const promise = mode === 'production'
-				? exec(`node ${cli} build`).then(() => ports.find(3000))
+				? exec(`node ${cli} build -l`).then(() => ports.find(3000))
 				: ports.find(3000).then(port => {
 					exec(`node ${cli} dev`);
 					return ports.wait(port).then(() => port);
@@ -160,6 +162,10 @@ function run({ mode, basepath = '' }) {
 
 				const dir = mode === 'production' ? 'build' : '.sapper';
 
+				if (mode === 'production') {
+					assert.ok(fs.existsSync('build/index.js'));
+				}
+
 				proc = require('child_process').fork(`${dir}/server.js`, {
 					cwd: process.cwd(),
 					env: {