diff --git a/web3.js/src/nonce-account.ts b/web3.js/src/nonce-account.ts
index 5b18b0cbc1..e3c7f41ff3 100644
--- a/web3.js/src/nonce-account.ts
+++ b/web3.js/src/nonce-account.ts
@@ -13,12 +13,25 @@ import {toBuffer} from './util/to-buffer';
  *
  * @internal
  */
-const NonceAccountLayout = BufferLayout.struct([
+const NonceAccountLayout = BufferLayout.struct<
+  Readonly<{
+    authorizedPubkey: Uint8Array;
+    feeCalculator: Readonly<{
+      lamportsPerSignature: number;
+    }>;
+    nonce: Uint8Array;
+    state: number;
+    version: number;
+  }>
+>([
   BufferLayout.u32('version'),
   BufferLayout.u32('state'),
   Layout.publicKey('authorizedPubkey'),
   Layout.publicKey('nonce'),
-  BufferLayout.struct([FeeCalculatorLayout], 'feeCalculator'),
+  BufferLayout.struct<Readonly<{lamportsPerSignature: number}>>(
+    [FeeCalculatorLayout],
+    'feeCalculator',
+  ),
 ]);
 
 export const NONCE_ACCOUNT_LENGTH = NonceAccountLayout.span;