diff --git a/.env.example b/.env.example
index bd7b864..b94e382 100644
--- a/.env.example
+++ b/.env.example
@@ -39,7 +39,7 @@ AUDIO_CHANNELS=2                        # Number of audio channels (default: 2)
 AVATAR_SIZE=64                          # User avatar size in pixels (default: 64)
 
 # === Webserver ===
-WEBSERVER_PORT=3001                     # Backend HTTP/WS server port (default: 3001)
+WEBSERVER_PORT=4001                     # Backend HTTP/WS server port (default: 4001)
 
 # === Connection ===
 VOICE_CONNECTION_TIMEOUT_MS=15000       # Voice connection timeout in ms (default: 15000)
diff --git a/infra/docker/docker-compose.yml b/infra/docker/docker-compose.yml
index b2a33cd..a576c79 100644
--- a/infra/docker/docker-compose.yml
+++ b/infra/docker/docker-compose.yml
@@ -33,9 +33,9 @@ services:
       - .env
     environment:
       NODE_ENV: production
-      WEBSERVER_PORT: 3000
+      WEBSERVER_PORT: 4000
     healthcheck:
-      test: ["CMD", "wget", "-qO-", "http://localhost:3000/api/health"]
+      test: ["CMD", "wget", "-qO-", "http://localhost:4000/api/health"]
       interval: 30s
       timeout: 10s
       start_period: 15s
diff --git a/services/backend/src/e2e.test.ts b/services/backend/src/e2e.test.ts
index 04662a4..9ec4cb8 100644
--- a/services/backend/src/e2e.test.ts
+++ b/services/backend/src/e2e.test.ts
@@ -1,10 +1,10 @@
 /**
  * E2E API tests — runs against a running backend instance.
- * Usage: API_BASE=http://localhost:3001 vitest run
+ * Usage: API_BASE=http://localhost:4001 vitest run
  */
 import { describe, expect, it } from "vitest";
 
-const BASE = process.env.API_BASE ?? "http://localhost:3001/api";
+const BASE = process.env.API_BASE ?? "http://localhost:4001/api";
 
 async function api(path: string, init?: RequestInit) {
   const res = await fetch(`${BASE}${path}`, {