diff --git a/src/index.js b/src/index.js
index f4f34f3..d3df487 100644
--- a/src/index.js
+++ b/src/index.js
@@ -13,21 +13,21 @@ const createTestServer = opts => Promise.all([
 	createCert(opts && opts.certificate)
 ])
 	.then(results => {
+		const port = results[0];
+		const sslPort = results[1];
 		const cert = results[2];
+
 		const app = express();
-		app.port = results[0];
-		app.sslPort = results[1];
 		app.caCert = cert.caKeys.cert;
-		app.host = 'localhost';
-		app.url = `http://${app.host}:${app.port}`;
-		app.sslUrl = `https://${app.host}:${app.sslPort}`;
+		app.url = `http://localhost:${port}`;
+		app.sslUrl = `https://localhost:${sslPort}`;
 
 		const server = http.createServer(app);
 		const sslServer = https.createServer(cert.keys, app);
 
 		app.listen = () => Promise.all([
-			pify(server.listen.bind(server))(app.port),
-			pify(sslServer.listen.bind(sslServer))(app.sslPort)
+			pify(server.listen.bind(server))(port),
+			pify(sslServer.listen.bind(sslServer))(sslPort)
 		]);
 		app.close = () => Promise.all([
 			pify(server.close.bind(server))(),
diff --git a/test/create-test-server.js b/test/create-test-server.js
index 59ea20b..318e645 100644
--- a/test/create-test-server.js
+++ b/test/create-test-server.js
@@ -13,11 +13,8 @@ test('createTestServer returns a Promise', t => {
 test('server instance exposes useful properties', async t => {
 	const server = await createTestServer();
 
-	t.is(server.host, 'localhost');
-	t.true(typeof server.port === 'number');
-	t.true(typeof server.sslPort === 'number');
-	t.is(server.url, `http://${server.host}:${server.port}`);
-	t.is(server.sslUrl, `https://${server.host}:${server.sslPort}`);
+	t.true(typeof server.url === 'string');
+	t.true(typeof server.sslUrl === 'string');
 	t.true(typeof server.caCert === 'string');
 	t.true(typeof server.listen === 'function');
 	t.true(typeof server.close === 'function');