diff --git a/types/rsocket-websocket-server/RSocketWebSocketServer.d.ts b/types/rsocket-websocket-server/RSocketWebSocketServer.d.ts
index 6a46b98d76..8a79a67d28 100644
--- a/types/rsocket-websocket-server/RSocketWebSocketServer.d.ts
+++ b/types/rsocket-websocket-server/RSocketWebSocketServer.d.ts
@@ -7,7 +7,7 @@ import * as ws from 'ws';
  * A WebSocket transport server.
  */
 export class RSocketWebSocketServer implements TransportServer {
-    constructor(options: ws.ServerOptions, encoders?: Encoders<any>);
+    constructor(options: ws.ServerOptions, encoders?: Encoders<any>, factory?: (options: ws.ServerOptions) => ws.Server);
     start(): Flowable<DuplexConnection>;
     stop(): void;
 }