diff --git a/packages/engine.io-client/lib/socket.ts b/packages/engine.io-client/lib/socket.ts
index 645a43622e..3c56bd6ec3 100644
--- a/packages/engine.io-client/lib/socket.ts
+++ b/packages/engine.io-client/lib/socket.ts
@@ -109,7 +109,7 @@ export interface SocketOptions {
    * @default ['polling','websocket', 'webtransport']
    */
   transports?:
-    | ("polling" | "websocket" | "webtransport" | string)[]
+    | ("polling" | "websocket" | "webtransport" | (string & {}))[]
     | TransportCtor[];
 
   /**