diff --git a/content/websockets/adapter.md b/content/websockets/adapter.md
index 6fdfd89901..e89527dd10 100644
--- a/content/websockets/adapter.md
+++ b/content/websockets/adapter.md
@@ -44,10 +44,12 @@ import { createAdapter } from '@socket.io/redis-adapter';
 import { createClient } from 'redis';
 
 export class RedisIoAdapter extends IoAdapter {
-  private adapterConstructor: ReturnType<typeof createAdapter>;
+  private adapterConstructor?: ReturnType<typeof createAdapter>;
 
   async connectToRedis(): Promise<void> {
-    const pubClient = createClient({ url: `redis://localhost:6379` });
+    const pubClient = createClient({
+      url: process.env.REDIS_URL || 'redis://localhost:6379',
+    });
     const subClient = pubClient.duplicate();
 
     await Promise.all([pubClient.connect(), subClient.connect()]);
@@ -55,9 +57,11 @@ export class RedisIoAdapter extends IoAdapter {
     this.adapterConstructor = createAdapter(pubClient, subClient);
   }
 
-  createIOServer(port: number, options?: ServerOptions): any {
+  override createIOServer(port: number, options?: ServerOptions) {
     const server = super.createIOServer(port, options);
-    server.adapter(this.adapterConstructor);
+    if (this.adapterConstructor) {
+      server.adapter(this.adapterConstructor);
+    }
     return server;
   }
 }