diff --git a/src/AcreBtcNew.ts b/src/AcreBtcNew.ts
index 6d5d184..105b2b4 100644
--- a/src/AcreBtcNew.ts
+++ b/src/AcreBtcNew.ts
@@ -313,6 +313,7 @@ export default class AcreBtcNew {
       s,
     };
   }
+
   cleanHexPrefix(hexString: string): string {
     let cleanedHex = hexString.startsWith("0x") ? hexString.slice(2) : hexString;
     if (cleanedHex.length % 2 !== 0) {
@@ -401,6 +402,33 @@ export default class AcreBtcNew {
       };
     }
 
+  /**
+   * Signs a ERC4361 hex-formatted message with the private key at
+   * the provided derivation path according to the Bitcoin Signature format
+   * and returns v, r, s.
+   */
+  async signERC4361Message({ path, messageHex }: { path: string; messageHex: string }): Promise<{
+    v: number;
+    r: string;
+    s: string;
+  }> {
+    const pathElements: number[] = pathStringToArray(path);
+    const message = Buffer.from(messageHex, "hex");
+    const sig = await this.client.signERC4361Message(message, pathElements);
+    console.log("sig", sig);
+    const buf = Buffer.from(sig, "base64");
+
+    const v = buf.readUInt8() - 27 - 4;
+    const r = buf.slice(1, 33).toString("hex");
+    const s = buf.slice(33, 65).toString("hex");
+
+    return {
+      v,
+      r,
+      s,
+    };
+  }
+
   /**
    * Calculates an output script along with public key and possible redeemScript
    * from a path and accountType. The accountPath must be a prefix of path.
diff --git a/src/newops/appClient.ts b/src/newops/appClient.ts
index 52c84aa..b6509cd 100644
--- a/src/newops/appClient.ts
+++ b/src/newops/appClient.ts
@@ -20,7 +20,8 @@ enum BitcoinIns {
   SIGN_PSBT = 0x04,
   GET_MASTER_FINGERPRINT = 0x05,
   SIGN_MESSAGE = 0x10,
-  SIGN_WITHDRAW = 0x11
+  SIGN_WITHDRAW = 0x11,
+  SIGN_ERC4361_MESSAGE = 0x12
 }
 
 enum FrameworkIns {
@@ -247,4 +248,30 @@ export class AppClient {
 
     return response.toString("base64")
   }
+
+  async signERC4361Message(message: Buffer, pathElements: number[]): Promise<string> {
+    if (pathElements.length > 6) {
+      throw new Error("Path too long. At most 6 levels allowed.");
+    }
+
+    const clientInterpreter = new ClientCommandInterpreter(() => {});
+
+    // prepare ClientCommandInterpreter
+    const nChunks = Math.ceil(message.length / 64);
+    const chunks: Buffer[] = [];
+    for (let i = 0; i < nChunks; i++) {
+      chunks.push(message.subarray(64 * i, 64 * i + 64));
+    }
+
+    clientInterpreter.addKnownList(chunks);
+    const chunksRoot = new Merkle(chunks.map(m => hashLeaf(m))).getRoot();
+
+    const response = await this.makeRequest(
+      BitcoinIns.SIGN_ERC4361_MESSAGE,
+      Buffer.concat([pathElementsToBuffer(pathElements), createVarint(message.length), chunksRoot]),
+      clientInterpreter,
+    );
+
+    return response.toString("base64");
+  }
 }
diff --git a/tests/newops/AcreBtcNew.test.ts b/tests/newops/AcreBtcNew.test.ts
index a948094..9cc9ea2 100644
--- a/tests/newops/AcreBtcNew.test.ts
+++ b/tests/newops/AcreBtcNew.test.ts
@@ -1,6 +1,7 @@
 /* eslint-disable @typescript-eslint/no-non-null-assertion */
 import { openTransportReplayer, RecordStore } from "@ledgerhq/hw-transport-mocker";
 import { TransportReplayer } from "@ledgerhq/hw-transport-mocker/lib/openTransportReplayer";
+import SpeculosTransport from "../speculosTransport";
 import ecc from "tiny-secp256k1";
 import { getXpubComponents, pathArrayToString } from "../../src/bip32";
 import AcreBtcNew from "../../src/AcreBtcNew";
@@ -57,9 +58,10 @@ test("testSignMessage", async () => {
   await testSignMessageReplayer("m/44'/0'/0'");
 });
 
-test("signWithdrawal", async () => {
-  await testSignWithdrawalReplayer();
-});
+
+test("Sign ERC-4361 message", async () => {
+  await testSignERC4361Speculos();
+}, 60 * 10 * 1000); // 10-minute timeout (60 seconds * 10 minutes * 1000 milliseconds)
 
 function testPaths(type: StandardPurpose): { ins: string[]; out?: string } {
   const basePath = `m/${type}/1'/0'/`;
@@ -228,6 +230,16 @@ async function testSignWithdrawalReplayer() {
   });
 }
 
+async function testSignERC4361Speculos() {
+  const transport = new SpeculosTransport('http://localhost:5000')
+  const client = new AppClient(transport);
+  const acreBtcNew = new AcreBtcNew(client);
+  const message = "stake.acre.fi wants you to sign in with your Bitcoin account:\nbc1q8fq0vs2f9g52cuk8px9f664qs0j7vtmx3r7wvx\n\n\nURI: https://stake.acre.fi\nVersion: 1\nNonce: cw73Kfdfn1lY42Jj8\nIssued At: 2024-10-01T11:03:05.707Z\nExpiration Time: 2024-10-08T11:03:05.707Z"
+  const path = "m/44'/0'/0'/0/0";
+  const result = await acreBtcNew.signERC4361Message({messageHex: Buffer.from(message).toString("hex"), path: path});
+  console.log(result);
+}
+
 function verifyGetWalletPublicKeyResult(
   result: { publicKey: string; bitcoinAddress: string; chainCode: string },
   expectedXpub: string,
@@ -318,4 +330,4 @@ class MockClient extends TestingClient {
   ): string {
     return walletPolicy.serialize().toString("hex") + change + addressIndex;
   }
-}
+}
\ No newline at end of file