diff --git a/README.md b/README.md
index 16b9c4b..a180a64 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ Program setup,
    please set the SIGNING_URL to your service endpoint. the mmsk would post every unsigned PMM/RFQV1/RFQV2 orders to your service. Remember to set the WALLET_ADDRESS as well. An example RFQV1 request is shown below:
     ```
     {
+      protocol: 'RFQV1',
       rfqOrder: {
         takerAddr: '0x87fca7135c1c54876a62dc4922da3ce45f38debf',
         makerAddr: '0x86B9F429C3Ef44c599EB560Eb531A0E3f2E36f64',
@@ -42,7 +43,6 @@ Program setup,
         salt: '54987026777386128963216107663301166813737035846370728350988439404382800511006'
       },
       userAddr: '0x87fca7135c1c54876a62dc4922da3ce45f38debf',
-      signer: '0xb5419119e04498C3eC43A9468D6480aF0DAE3A0c',
       chainId: 1,
       rfqAddr: '0xfD6C2d2499b1331101726A8AC68CCc9Da3fAB54F'
     }
diff --git a/package.json b/package.json
index 2e96bdd..2bde119 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@consenlabs/tokenlon-mmsk",
-  "version": "5.3.0",
+  "version": "5.3.1",
   "description": "Tokenlon market maker server kit",
   "author": "imToken PTE. LTD.",
   "license": "MIT",
diff --git a/src/handler/version.ts b/src/handler/version.ts
index d299a81..24bc157 100644
--- a/src/handler/version.ts
+++ b/src/handler/version.ts
@@ -1,4 +1,4 @@
-export const VERSION = '5.3.0'
+export const VERSION = '5.3.1'
 
 export const version = (ctx) => {
   ctx.body = {
diff --git a/src/signer/pmmv5.ts b/src/signer/pmmv5.ts
index 9a713ff..2adaa82 100644
--- a/src/signer/pmmv5.ts
+++ b/src/signer/pmmv5.ts
@@ -10,6 +10,7 @@ import * as ethUtils from 'ethereumjs-util'
 import { utils, Wallet } from 'ethers'
 import axios from 'axios'
 import { BigNumber, orderBNToString } from '../utils'
+import { Protocol } from '../types'
 
 const EIP712_ORDER_SCHEMA = {
   name: 'Order',
@@ -160,12 +161,12 @@ export const buildSignedOrder = async (
         : await signByMMPSigner(orderSignDigest, userAddr, feeFactor, signer)
   } else {
     makerWalletSignature = await forwardUnsignedOrder(signingUrl, {
+      protocol: Protocol.PMMV5,
       pmmOrder: o,
       feeFactor: feeFactor,
       orderHash: orderHash,
       orderSignDigest: orderSignDigest,
       userAddr: userAddr,
-      signer: signer.address,
       chainId: chainId,
       pmmAddr: pmm,
     })
diff --git a/src/signer/rfqv1.ts b/src/signer/rfqv1.ts
index 39d13da..bfa6b10 100644
--- a/src/signer/rfqv1.ts
+++ b/src/signer/rfqv1.ts
@@ -6,6 +6,7 @@ import { RFQOrder, WalletType } from './types'
 import * as ethUtils from 'ethereumjs-util'
 import { SignatureType } from './types'
 import axios from 'axios'
+import { Protocol } from '../types'
 
 // spec of RFQV1
 // - taker address point to userAddr
@@ -188,9 +189,9 @@ export const buildSignedOrder = async (
     }
   } else {
     makerWalletSignature = await forwardUnsignedOrder(signingUrl, {
+      protocol: Protocol.RFQV1,
       rfqOrder: rfqOrder,
       userAddr: userAddr,
-      signer: signer.address,
       chainId: chainId,
       rfqAddr: rfqAddr,
     })
diff --git a/src/signer/rfqv2.ts b/src/signer/rfqv2.ts
index fbd0b5e..b13db77 100644
--- a/src/signer/rfqv2.ts
+++ b/src/signer/rfqv2.ts
@@ -6,6 +6,7 @@ import * as ethUtils from 'ethereumjs-util'
 import axios from 'axios'
 import { generatePseudoRandomSalt } from '0x-v2-order-utils'
 import { signWithUserAndFee } from './pmmv5'
+import { Protocol } from '../types'
 
 // spec of RFQV2
 // - taker address point to userAddr
@@ -175,9 +176,9 @@ export const buildSignedOrder = async (
     }
   } else {
     makerWalletSignature = await forwardUnsignedOrder(signingUrl, {
+      protocol: Protocol.RFQV2,
       rfqOrder: rfqOrder,
       userAddr: userAddr,
-      signer: signer.address,
       chainId: chainId,
       rfqAddr: rfqAddr,
     })