diff --git a/paymaster/src/rpcMethods.ts b/paymaster/src/rpcMethods.ts
index e981580..313daac 100644
--- a/paymaster/src/rpcMethods.ts
+++ b/paymaster/src/rpcMethods.ts
@@ -5,21 +5,19 @@ import { whitelistAll, whitelistedAddresses } from './config';
 import dotenv from 'dotenv';
 dotenv.config();
 
-export interface UserOperation {
+export interface PackedUserOperation {
     sender: string
     nonce: BigNumberish
     initCode: BytesLike
     callData: BytesLike
-    callGasLimit: BigNumberish
-    verificationGasLimit: BigNumberish
+    accountGasLimits: BytesLike
     preVerificationGas: BigNumberish
-    maxFeePerGas: BigNumberish
-    maxPriorityFeePerGas: BigNumberish
+    gasFees: BytesLike
     paymasterAndData: BytesLike
     signature: BytesLike
 }
 
-export async function sponsorTransaction(userOp: UserOperation): Promise<UserOperation> {
+export async function sponsorTransaction(userOp: PackedUserOperation): Promise<PackedUserOperation> {
     const paymasterAddress = process.env.PAYMASTER_ADDRESS as string;
     const provider = new ethers.JsonRpcProvider(process.env.RPC_URL as string);
     const signer = new ethers.Wallet(process.env.PRIVATE_KEY as string);
diff --git a/paymaster/src/server.ts b/paymaster/src/server.ts
index 835f555..33561b8 100644
--- a/paymaster/src/server.ts
+++ b/paymaster/src/server.ts
@@ -1,12 +1,12 @@
 import express, { Express, Request, Response } from 'express';
 import bodyParser from 'body-parser';
 import cors from 'cors';
-import { sponsorTransaction, UserOperation } from './rpcMethods';
+import { sponsorTransaction, PackedUserOperation } from './rpcMethods';
 
 type JsonRpcRequestBody = {
     id: number;
     method: string;
-    params: UserOperation;
+    params: PackedUserOperation;
 };
 
 const app: Express = express();
diff --git a/paymaster/test/tests.ts b/paymaster/test/tests.ts
index 97b68ac..a51a597 100644
--- a/paymaster/test/tests.ts
+++ b/paymaster/test/tests.ts
@@ -1,7 +1,7 @@
 import { ethers } from 'ethers';
 import dotenv from 'dotenv';
 import axios from 'axios';
-import { UserOperation } from '../src/rpcMethods';
+import { PackedUserOperation } from '../src/rpcMethods';
 import { simpleAccountAbi, simpleAccountFactoryAbi, paymasterAbi, entrypointAbi } from '../src/abis';
 dotenv.config();
 
@@ -42,16 +42,20 @@ async function main() {
     const callData = simpleAccount.interface.encodeFunctionData("execute", [to, value, data]);
 
     // Construct UserOp
-    let userOp: UserOperation = {
+    let userOp: PackedUserOperation = {
         sender: simpleAccountAddress,
         nonce: Number(await paymaster.senderNonce(simpleAccountAddress)),
         initCode: initCode,
         callData: callData,
-        callGasLimit: ethers.toBeHex(3_000_000), // hardcode it for now at a high value,
-        verificationGasLimit: ethers.toBeHex(3_000_000), // hardcode it for now at a high value,
+        accountGasLimits: ethers.concat([
+            ethers.toBeHex(3_000_000), // callGasLimit: hardcode it for now at a high value,
+            ethers.toBeHex(3_000_000) // verificationGasLimit: hardcode it for now at a high value,
+        ]),
         preVerificationGas: ethers.toBeHex(2_000_000), // hardcode it for now at a high value,
-        maxFeePerGas: ethers.toBeHex(2e9),
-        maxPriorityFeePerGas: ethers.toBeHex(1e9),
+        gasFees: ethers.concat([
+            ethers.toBeHex(2e9), // maxFeePerGas
+            ethers.toBeHex(1e9) // maxPriorityFeePerGas
+        ]),
         paymasterAndData: ethers.concat([
             paymasterAddress,
             '0x' + '00'.repeat(64),