diff --git a/packages/engine.io/lib/userver.ts b/packages/engine.io/lib/userver.ts
index e8fb47f58..f27c9f2e2 100644
--- a/packages/engine.io/lib/userver.ts
+++ b/packages/engine.io/lib/userver.ts
@@ -88,7 +88,7 @@ export class uServer extends BaseServer {
         },
         message: (ws, message, isBinary) => {
           ws.getUserData().transport.onData(
-            isBinary ? message : Buffer.from(message).toString(),
+            isBinary ? message.slice(0, message.byteLength) : Buffer.from(message).toString(),
           );
         },
         close: (ws, code, message) => {
diff --git a/packages/engine.io/wrapper.mjs b/packages/engine.io/wrapper.mjs
index d0b2debf7..d13ab0e02 100644
--- a/packages/engine.io/wrapper.mjs
+++ b/packages/engine.io/wrapper.mjs
@@ -7,4 +7,5 @@ export {
   attach,
   parser,
   protocol,
+  uServer
 } from "./build/engine.io.js";