diff --git a/client/main.ts b/client/main.ts
index 999bcc1..1ca93fc 100755
--- a/client/main.ts
+++ b/client/main.ts
@@ -14,18 +14,27 @@ import {
 const log = log_from(import.meta);
 
 async function main() {
+	const args = parse_args(Deno.args);
+
 	log("Client starting.");
-	const interface_ = await ServerInterface.connect(9999);
-	new InputHandler(interface_.outputs).spin();
+	const interface_ = await ServerInterface.connect(args.port);
 	const display = new DisplayHandler(interface_.outputs);
-	display.spin();
 	new MsgHandler(interface_.inputs, display).spin();
+	new InputHandler(interface_.outputs).spin();
+	display.spin();
 	log("Connected.");
 
 	interface_.outputs.send({ kind: "ping", content: { message: "Machin." } });
 	log("Sent ping.");
 }
 
+function parse_args(args: string[]) {
+	const [port_] = args;
+	let port = 9999;
+	if (port_ !== undefined) port = parseInt(port_);
+	return { port };
+}
+
 class MsgHandler {
 	receiver;
 	display;
diff --git a/server/main.ts b/server/main.ts
index 1a67098..5e88b52 100755
--- a/server/main.ts
+++ b/server/main.ts
@@ -10,6 +10,8 @@ import { enemy_plugin } from "./entities/enemy.ts";
 const log = log_from(import.meta);
 
 async function main() {
+	const args = parse_args(Deno.args);
+
 	log("Starting.");
 	const engine = new Engine();
 	enemy_plugin(engine);
@@ -18,12 +20,18 @@ async function main() {
 	engine.run(await sys_spawn_structure("../data/structures/houses.txt", v2(2, 2)));
 	engine.run(sys_spawn_enemy(v2(1, 1)));
 
-	const port = 9999;
-	const gateway = new Gateway(port);
+	const gateway = new Gateway(args.port);
 	log("Awaiting connection.");
 	for await (const client of gateway.accept()) {
 		Session.init(client, engine).start();
 	}
 }
 
+function parse_args(args: string[]) {
+	const [port_] = args;
+	let port = 9999;
+	if (port_ !== undefined) port = parseInt(port_);
+	return { port };
+}
+
 if (import.meta.main) await main();