diff --git a/packages/site/src/components/Sovereign.tsx b/packages/site/src/components/Sovereign.tsx
index 3b62f93..befb533 100644
--- a/packages/site/src/components/Sovereign.tsx
+++ b/packages/site/src/components/Sovereign.tsx
@@ -17,6 +17,7 @@ type SovereignState = {
   curve: CurveSelectorState;
   keyId: number;
   message?: string;
+  nonce?: number;
   request?: string;
   response?: string;
 };
@@ -27,6 +28,7 @@ export const Sovereign = () => {
     curve: `secp256k1`,
     keyId: 0,
     message: 'Some signature message...',
+    nonce: 0,
   };
   const [state, setState] = useState(initialState);
 
@@ -97,10 +99,29 @@ export const Sovereign = () => {
           cols={40}
         />
       </div>
+      <div>Nonce:</div>
+      <div>
+        <input
+          type="number"
+          value={state.nonce}
+          onChange={(ev) => {
+            const { value } = ev.target;
+
+            // Allow only positive integers (whole numbers greater than or equal to zero)
+            const regex = /^[0-9\b]+$/u; // Allows digits only
+            if (value === '' || regex.test(value)) {
+              setState({
+                ...state,
+                nonce: parseInt(value, 10),
+              });
+            }
+          }}
+        />
+      </div>
       <div>
         <ExecuteButton
           onClick={async () => {
-            const { method, curve, keyId, message } = state;
+            const { method, curve, keyId, message, nonce } = state;
 
             const path = ['m', "44'", "1551'"];
             path.push(keyId.toString());
@@ -114,6 +135,7 @@ export const Sovereign = () => {
                 transaction: {
                   message: message || '',
                 },
+                nonce,
               };
             } else {
               params = {
diff --git a/packages/snap/README.md b/packages/snap/README.md
index c508bef..f08af8e 100644
--- a/packages/snap/README.md
+++ b/packages/snap/README.md
@@ -45,6 +45,7 @@ Will emit a confirmation dialog for the user.
 - `curve`: The curve of the public key (`secp256k1` or `ed25519`).
 - `schema`: A [borsh](https://www.npmjs.com/package/borsh) schema for the transaction.
 - `transaction`: A transaction to be serialized using the provided schema. The signature will be performed over the serialized transaction.
+- `nonce`: An unsigned 64-bits number to be appended to the serialized transaction.
 
 ##### Example
 
@@ -90,12 +91,13 @@ const response = request({
         amount: 1582,
       },
     },
+    nonce: 0,
   },
 });
 
 if (
   !response ===
-  '0xfd2e4b23a3e3f498664af355b341e833324276270a13f9647dd1f043248f92fccaa037d4cfc9d23f13a295f7d505ee13afb2b10cea548890678f9002947cbb0a'
+  '0xe563b3d772572e57bff43e31e449dbc8e98f7580fea10b2ad1ad8278b3edcf5ff5b3a24b85cef3192fcd70452c58e7c968e500da9e290aefadf5ef22a4efbf0d',
 ) {
   throw new Error('Invalid signature');
 }
diff --git a/packages/snap/package.json b/packages/snap/package.json
index ee36796..6c696ba 100644
--- a/packages/snap/package.json
+++ b/packages/snap/package.json
@@ -34,7 +34,8 @@
     "@noble/ed25519": "^1.6.0",
     "@noble/secp256k1": "^1.7.1",
     "borsh": "^1.0.0",
-    "buffer": "^6.0.3"
+    "buffer": "^6.0.3",
+    "int64-buffer": "^1.0.1"
   },
   "devDependencies": {
     "@jest/globals": "^29.5.0",
diff --git a/packages/snap/snap.manifest.json b/packages/snap/snap.manifest.json
index 96455b2..fd05677 100644
--- a/packages/snap/snap.manifest.json
+++ b/packages/snap/snap.manifest.json
@@ -7,7 +7,7 @@
     "url": "https://github.com/Sovereign-Labs/sov-snap.git"
   },
   "source": {
-    "shasum": "WZco6V2pvJMpitcOysOcWYoVpGTBAn7cSdHRGM6MRu0=",
+    "shasum": "wOP1ZGD2ciBIysiXTThBibt0cTkaxNKbsFCLXk+Si/c=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",
diff --git a/packages/snap/src/index.test.ts b/packages/snap/src/index.test.ts
index 646e5a3..9c9db92 100644
--- a/packages/snap/src/index.test.ts
+++ b/packages/snap/src/index.test.ts
@@ -84,6 +84,7 @@ describe('onRpcRequest', () => {
               payload: Array(176).fill(5),
             },
           },
+          nonce: 26,
         },
       });
 
@@ -114,6 +115,7 @@ describe('onRpcRequest', () => {
               amount: 1582,
             },
           },
+          nonce: 0,
         },
       });
 
@@ -122,7 +124,7 @@ describe('onRpcRequest', () => {
       await ui.ok();
 
       expect(await response).toRespondWith(
-        '0xfd2e4b23a3e3f498664af355b341e833324276270a13f9647dd1f043248f92fccaa037d4cfc9d23f13a295f7d505ee13afb2b10cea548890678f9002947cbb0a',
+        '0xe563b3d772572e57bff43e31e449dbc8e98f7580fea10b2ad1ad8278b3edcf5ff5b3a24b85cef3192fcd70452c58e7c968e500da9e290aefadf5ef22a4efbf0d',
       );
 
       await close();
diff --git a/packages/snap/src/index.ts b/packages/snap/src/index.ts
index d61f5ce..2d0230f 100644
--- a/packages/snap/src/index.ts
+++ b/packages/snap/src/index.ts
@@ -6,6 +6,7 @@ import { add0x, assert, bytesToHex, remove0x } from '@metamask/utils';
 import { sign as signEd25519 } from '@noble/ed25519';
 import { sign as signSecp256k1 } from '@noble/secp256k1';
 import { serialize } from 'borsh';
+import { Uint64LE } from 'int64-buffer';
 
 import type { GetBip32PublicKeyParams, SignTransactionParams } from './types';
 
@@ -28,9 +29,11 @@ export const onRpcRequest: OnRpcRequestHandler = async ({ request }) => {
       });
 
     case 'signTransaction': {
-      const { schema, transaction, curve, ...params } =
+      const { schema, transaction, nonce, curve, ...params } =
         request.params as SignTransactionParams;
 
+      const nonceLe = new Uint64LE(nonce);
+      const nonceBytes = nonceLe.toBuffer();
       const serializedTransaction = serialize(schema, transaction);
 
       const json = await snap.request({
@@ -58,11 +61,11 @@ export const onRpcRequest: OnRpcRequestHandler = async ({ request }) => {
           type: DialogType.Confirmation,
           content: panel([
             heading('Signature request'),
-            text(
-              `Do you want to ${curve} sign ${JSON.stringify(
-                transaction,
-              )} with the following public key?`,
-            ),
+            text(`Do you want to ${curve} sign`),
+            copyable(JSON.stringify(transaction)),
+            text(`with nonce`),
+            copyable(String(nonce)),
+            text(`and the following public key?`),
             copyable(add0x(node.publicKey)),
           ]),
         },
@@ -73,14 +76,18 @@ export const onRpcRequest: OnRpcRequestHandler = async ({ request }) => {
       }
 
       const privateKey = remove0x(node.privateKey);
+      const signedTransaction = new Uint8Array([
+        ...serializedTransaction,
+        ...nonceBytes,
+      ]);
 
       let signed;
       switch (curve) {
         case 'ed25519':
-          signed = await signEd25519(serializedTransaction, privateKey);
+          signed = await signEd25519(signedTransaction, privateKey);
           break;
         case 'secp256k1':
-          signed = await signSecp256k1(serializedTransaction, privateKey);
+          signed = await signSecp256k1(signedTransaction, privateKey);
           break;
         default:
           throw new Error(`Unsupported curve: ${String(curve)}.`);
diff --git a/packages/snap/src/types.ts b/packages/snap/src/types.ts
index 1b2bffb..0bb5bd5 100644
--- a/packages/snap/src/types.ts
+++ b/packages/snap/src/types.ts
@@ -45,6 +45,11 @@ export type SignTransactionParams = {
    */
   transaction: any;
 
+  /**
+   * The nonce of the transaction.
+   */
+  nonce: number;
+
   /**
    * The BIP-32 path to the account.
    */
diff --git a/yarn.lock b/yarn.lock
index 6fed90c..1aa2258 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -14277,6 +14277,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"int64-buffer@npm:^1.0.1":
+  version: 1.0.1
+  resolution: "int64-buffer@npm:1.0.1"
+  checksum: 9962be285f4a0d6bd8f6fba3cffcfd80b15848af370bd9ec6cb2d9c8a8adf83b230cdf66b694f87c992c1a33724385b28ba7cac61602a7fcf9b9c8691015c7e2
+  languageName: node
+  linkType: hard
+
 "internal-slot@npm:^1.0.3":
   version: 1.0.3
   resolution: "internal-slot@npm:1.0.3"
@@ -20888,6 +20895,7 @@ __metadata:
     eslint-plugin-jsdoc: ^39.2.9
     eslint-plugin-node: ^11.1.0
     eslint-plugin-prettier: ^4.2.1
+    int64-buffer: ^1.0.1
     jest: ^29.5.0
     prettier: ^2.2.1
     prettier-plugin-packagejson: ^2.2.11