diff --git a/lib/socket.ts b/lib/socket.ts
index 1c387235f..81b974821 100644
--- a/lib/socket.ts
+++ b/lib/socket.ts
@@ -7,6 +7,7 @@ import { Emitter } from "@socket.io/component-emitter";
 import { protocol } from "engine.io-parser";
 import type { Packet, BinaryType, PacketType, RawData } from "engine.io-parser";
 import { CloseDetails, Transport } from "./transport.js";
+import { defaultBinaryType } from "./transports/websocket-constructor.js";
 
 const debug = debugModule("engine.io-client:socket"); // debug()
 
@@ -253,7 +254,7 @@ export class Socket extends Emitter<
 > {
   public id: string;
   public transport: Transport;
-  public binaryType: BinaryType;
+  public binaryType: BinaryType = defaultBinaryType;
   public readyState: SocketState;
   public writeBuffer: Packet[] = [];
 
diff --git a/lib/transports/websocket.ts b/lib/transports/websocket.ts
index 33d78724d..45bc47d1e 100644
--- a/lib/transports/websocket.ts
+++ b/lib/transports/websocket.ts
@@ -1,9 +1,7 @@
 import { Transport } from "../transport.js";
-import { encode } from "../contrib/parseqs.js";
 import { yeast } from "../contrib/yeast.js";
 import { pick } from "../util.js";
 import {
-  defaultBinaryType,
   nextTick,
   usingBrowserWebSocket,
   WebSocket,
@@ -84,7 +82,7 @@ export class WS extends Transport {
       return this.emitReserved("error", err);
     }
 
-    this.ws.binaryType = this.socket.binaryType || defaultBinaryType;
+    this.ws.binaryType = this.socket.binaryType;
 
     this.addEventListeners();
   }
diff --git a/lib/transports/webtransport.ts b/lib/transports/webtransport.ts
index 9f411a636..7996a2f05 100644
--- a/lib/transports/webtransport.ts
+++ b/lib/transports/webtransport.ts
@@ -43,8 +43,7 @@ export class WT extends Transport {
       this.transport.createBidirectionalStream().then((stream) => {
         const decoderStream = createPacketDecoderStream(
           Number.MAX_SAFE_INTEGER,
-          // TODO expose binarytype
-          "arraybuffer"
+          this.socket.binaryType
         );
         const reader = stream.readable.pipeThrough(decoderStream).getReader();
 
diff --git a/test/webtransport.mjs b/test/webtransport.mjs
index 1ff7b917b..69d92d808 100644
--- a/test/webtransport.mjs
+++ b/test/webtransport.mjs
@@ -260,12 +260,14 @@ describe("WebTransport", () => {
     });
   });
 
-  it("should send some binary data (server to client)", (done) => {
+  it("should send some binary data (server to client) (as ArrayBuffer)", (done) => {
     setup({}, ({ engine, h3Server, certificate }) => {
       const socket = createSocket(h3Server.port, certificate, {
         transports: ["webtransport"],
       });
 
+      socket.binaryType = "arraybuffer";
+
       engine.on("connection", (serverSocket) => {
         serverSocket.send(Uint8Array.from([1, 2, 3]));
       });
@@ -278,4 +280,23 @@ describe("WebTransport", () => {
       });
     });
   });
+
+  it("should send some binary data (server to client) (as Buffer)", (done) => {
+    setup({}, ({ engine, h3Server, certificate }) => {
+      const socket = createSocket(h3Server.port, certificate, {
+        transports: ["webtransport"],
+      });
+
+      engine.on("connection", (serverSocket) => {
+        serverSocket.send(Uint8Array.from([1, 2, 3]));
+      });
+
+      socket.on("message", (data) => {
+        expect(Buffer.isBuffer(data)).to.be(true);
+        expect(data).to.eql(Uint8Array.of(1, 2, 3));
+
+        success(engine, h3Server, done);
+      });
+    });
+  });
 });