diff --git a/contracts/coordinator/test/coordinator.ts b/contracts/coordinator/test/coordinator.ts
index 912d48d922..1fe84e3184 100644
--- a/contracts/coordinator/test/coordinator.ts
+++ b/contracts/coordinator/test/coordinator.ts
@@ -21,7 +21,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, orderHashUtils } from '@0x/order-utils';
 import { RevertReason, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import * as chai from 'chai';
 import { LogWithDecodedArgs } from 'ethereum-types';
 
@@ -33,6 +33,7 @@ const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 web3Wrapper.abiDecoder.addABI(exchangeArtifacts.Exchange.compilerOutput.abi);
 // tslint:disable:no-unnecessary-type-assertion
 describe('Coordinator tests', () => {
+    let chainId: number;
     let makerAddress: string;
     let owner: string;
     let takerAddress: string;
@@ -58,6 +59,7 @@ describe('Coordinator tests', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress] = accounts.slice(0, 4));
 
@@ -75,6 +77,7 @@ describe('Coordinator tests', () => {
             provider,
             txDefaults,
             assetDataUtils.encodeERC20AssetData(zrxToken.address),
+            new BigNumber(chainId),
         );
 
         await web3Wrapper.awaitTransactionSuccessAsync(
@@ -92,12 +95,14 @@ describe('Coordinator tests', () => {
             provider,
             txDefaults,
             exchange.address,
+            new BigNumber(chainId),
         );
 
         // Configure order defaults
         const defaultOrderParams = {
             ...devConstants.STATIC_ORDER_PARAMS,
             exchangeAddress: exchange.address,
+            chainId,
             senderAddress: coordinatorContract.address,
             makerAddress,
             feeRecipientAddress,
@@ -108,9 +113,21 @@ describe('Coordinator tests', () => {
         const takerPrivateKey = devConstants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(takerAddress)];
         const feeRecipientPrivateKey = devConstants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(feeRecipientAddress)];
         orderFactory = new OrderFactory(makerPrivateKey, defaultOrderParams);
-        makerTransactionFactory = new TransactionFactory(makerPrivateKey, exchange.address);
-        takerTransactionFactory = new TransactionFactory(takerPrivateKey, exchange.address);
-        approvalFactory = new ApprovalFactory(feeRecipientPrivateKey, coordinatorContract.address);
+        makerTransactionFactory = new TransactionFactory(
+            makerPrivateKey,
+            exchange.address,
+            chainId,
+        );
+        takerTransactionFactory = new TransactionFactory(
+            takerPrivateKey,
+            exchange.address,
+            chainId,
+        );
+        approvalFactory = new ApprovalFactory(
+            feeRecipientPrivateKey,
+            coordinatorContract.address,
+            chainId,
+        );
     });
     beforeEach(async () => {
         await blockchainLifecycle.startAsync();
diff --git a/contracts/coordinator/test/libs.ts b/contracts/coordinator/test/libs.ts
index 8c08f0ec59..1ef208b637 100644
--- a/contracts/coordinator/test/libs.ts
+++ b/contracts/coordinator/test/libs.ts
@@ -1,7 +1,7 @@
 import { addressUtils, chaiSetup, constants, provider, txDefaults, web3Wrapper } from '@0x/contracts-test-utils';
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { transactionHashUtils } from '@0x/order-utils';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import * as chai from 'chai';
 
 import { artifacts, CoordinatorContract, hashUtils } from '../src';
@@ -12,6 +12,7 @@ const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 
 describe('Libs tests', () => {
     let coordinatorContract: CoordinatorContract;
+    let chainId: number;
     const exchangeAddress = addressUtils.generatePseudoRandomAddress();
 
     before(async () => {
@@ -21,11 +22,13 @@ describe('Libs tests', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         coordinatorContract = await CoordinatorContract.deployFrom0xArtifactAsync(
             artifacts.Coordinator,
             provider,
             txDefaults,
             exchangeAddress,
+            new BigNumber(chainId),
         );
     });
     beforeEach(async () => {
@@ -39,6 +42,7 @@ describe('Libs tests', () => {
         it('should return the correct transaction hash', async () => {
             const tx = {
                 verifyingContractAddress: exchangeAddress,
+                chainId,
                 salt: new BigNumber(0),
                 signerAddress: constants.NULL_ADDRESS,
                 data: '0x1234',
@@ -53,6 +57,7 @@ describe('Libs tests', () => {
         it('should return the correct approval hash', async () => {
             const signedTx = {
                 verifyingContractAddress: exchangeAddress,
+                chainId,
                 salt: new BigNumber(0),
                 signerAddress: constants.NULL_ADDRESS,
                 data: '0x1234',
@@ -69,6 +74,7 @@ describe('Libs tests', () => {
             const expectedApprovalHash = hashUtils.getApprovalHashHex(
                 signedTx,
                 coordinatorContract.address,
+                chainId,
                 txOrigin,
                 approvalExpirationTimeSeconds,
             );
diff --git a/contracts/coordinator/test/mixins.ts b/contracts/coordinator/test/mixins.ts
index a500333048..45f7961f1d 100644
--- a/contracts/coordinator/test/mixins.ts
+++ b/contracts/coordinator/test/mixins.ts
@@ -12,7 +12,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { transactionHashUtils } from '@0x/order-utils';
 import { RevertReason, SignatureType, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import * as chai from 'chai';
 import * as ethUtil from 'ethereumjs-util';
 
@@ -23,6 +23,7 @@ const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 
 describe('Mixins tests', () => {
+    let chainId: number;
     let transactionSignerAddress: string;
     let approvalSignerAddress1: string;
     let approvalSignerAddress2: string;
@@ -40,16 +41,19 @@ describe('Mixins tests', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         mixins = await CoordinatorContract.deployFrom0xArtifactAsync(
             artifacts.Coordinator,
             provider,
             txDefaults,
             exchangeAddress,
+            new BigNumber(chainId),
         );
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         [transactionSignerAddress, approvalSignerAddress1, approvalSignerAddress2] = accounts.slice(0, 3);
         defaultOrder = {
             exchangeAddress: devConstants.NULL_ADDRESS,
+            chainId,
             makerAddress: devConstants.NULL_ADDRESS,
             takerAddress: devConstants.NULL_ADDRESS,
             senderAddress: mixins.address,
@@ -68,9 +72,21 @@ describe('Mixins tests', () => {
             devConstants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(transactionSignerAddress)];
         const approvalSignerPrivateKey1 = devConstants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(approvalSignerAddress1)];
         const approvalSignerPrivateKey2 = devConstants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(approvalSignerAddress2)];
-        transactionFactory = new TransactionFactory(transactionSignerPrivateKey, exchangeAddress);
-        approvalFactory1 = new ApprovalFactory(approvalSignerPrivateKey1, mixins.address);
-        approvalFactory2 = new ApprovalFactory(approvalSignerPrivateKey2, mixins.address);
+        transactionFactory = new TransactionFactory(
+            transactionSignerPrivateKey,
+            exchangeAddress,
+            chainId,
+        );
+        approvalFactory1 = new ApprovalFactory(
+            approvalSignerPrivateKey1,
+            mixins.address,
+            chainId,
+        );
+        approvalFactory2 = new ApprovalFactory(
+            approvalSignerPrivateKey2,
+            mixins.address,
+            chainId,
+        );
     });
     beforeEach(async () => {
         await blockchainLifecycle.startAsync();
diff --git a/contracts/coordinator/test/utils/approval_factory.ts b/contracts/coordinator/test/utils/approval_factory.ts
index f0c5ea145d..9e35b81a37 100644
--- a/contracts/coordinator/test/utils/approval_factory.ts
+++ b/contracts/coordinator/test/utils/approval_factory.ts
@@ -8,10 +8,16 @@ import { hashUtils, SignedCoordinatorApproval } from './index';
 export class ApprovalFactory {
     private readonly _privateKey: Buffer;
     private readonly _verifyingContractAddress: string;
+    private readonly _chainId: number;
 
-    constructor(privateKey: Buffer, verifyingContractAddress: string) {
+    constructor(
+        privateKey: Buffer,
+        verifyingContractAddress: string,
+        chainId: number,
+    ) {
         this._privateKey = privateKey;
         this._verifyingContractAddress = verifyingContractAddress;
+        this._chainId = chainId;
     }
 
     public newSignedApproval(
@@ -23,6 +29,7 @@ export class ApprovalFactory {
         const approvalHashBuff = hashUtils.getApprovalHashBuffer(
             transaction,
             this._verifyingContractAddress,
+            this._chainId,
             txOrigin,
             approvalExpirationTimeSeconds,
         );
diff --git a/contracts/coordinator/test/utils/hash_utils.ts b/contracts/coordinator/test/utils/hash_utils.ts
index 6e2ca8141c..e16736e70e 100644
--- a/contracts/coordinator/test/utils/hash_utils.ts
+++ b/contracts/coordinator/test/utils/hash_utils.ts
@@ -6,7 +6,6 @@ import * as _ from 'lodash';
 export const hashUtils = {
     getApprovalHashBuffer(
         transaction: SignedZeroExTransaction,
-        chainId: BigNumber,
         verifyingContractAddress: string,
         txOrigin: string,
         approvalExpirationTimeSeconds: BigNumber,
@@ -22,7 +21,6 @@ export const hashUtils = {
     },
     getApprovalHashHex(
         transaction: SignedZeroExTransaction,
-        chainId: BigNumber,
         verifyingContractAddress: string,
         txOrigin: string,
         approvalExpirationTimeSeconds: BigNumber,
@@ -30,7 +28,6 @@ export const hashUtils = {
         const hashHex = `0x${hashUtils
             .getApprovalHashBuffer(
                 transaction,
-                chainId,
                 verifyingContractAddress,
                 txOrigin,
                 approvalExpirationTimeSeconds)
diff --git a/contracts/exchange-libs/package.json b/contracts/exchange-libs/package.json
index 5954916aa5..e7b41863f8 100644
--- a/contracts/exchange-libs/package.json
+++ b/contracts/exchange-libs/package.json
@@ -34,7 +34,7 @@
         "lint-contracts": "solhint -c ../.solhint.json contracts/**/**/**/**/*.sol"
     },
     "config": {
-        "abis": "./generated-artifacts/@(LibAbiEncoder|LibAssetProxyErrors|LibConstants|LibEIP712|LibFillResults|LibMath|LibOrder|TestLibs).json",
+        "abis": "./generated-artifacts/@(LibAbiEncoder|LibAssetProxyErrors|LibConstants|LibEIP712|LibEIP712ExchangeDomainConstants|LibEIP712ExchangeDomain|LibFillResults|LibMath|LibOrder|TestLibs).json",
         "abis:comment": "This list is auto-generated by contracts-gen. Don't edit manually."
     },
     "repository": {
diff --git a/contracts/exchange-libs/test/exchange_libs.ts b/contracts/exchange-libs/test/exchange_libs.ts
index b613231895..d713dfe268 100644
--- a/contracts/exchange-libs/test/exchange_libs.ts
+++ b/contracts/exchange-libs/test/exchange_libs.ts
@@ -10,7 +10,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, orderHashUtils } from '@0x/order-utils';
 import { SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import * as chai from 'chai';
 
 import { TestLibsContract } from '../generated-wrappers/test_libs';
@@ -22,6 +22,7 @@ const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 
 describe('Exchange libs', () => {
+    let chainId: number;
     let signedOrder: SignedOrder;
     let orderFactory: OrderFactory;
     let libs: TestLibsContract;
@@ -35,11 +36,18 @@ describe('Exchange libs', () => {
     before(async () => {
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         const makerAddress = accounts[0];
-        libs = await TestLibsContract.deployFrom0xArtifactAsync(artifacts.TestLibs, provider, txDefaults);
+        chainId = await providerUtils.getChainIdAsync(provider);
+        libs = await TestLibsContract.deployFrom0xArtifactAsync(
+            artifacts.TestLibs,
+            provider,
+            txDefaults,
+            new BigNumber(chainId),
+        );
 
         const defaultOrderParams = {
             ...constants.STATIC_ORDER_PARAMS,
             exchangeAddress: libs.address,
+            chainId,
             makerAddress,
             feeRecipientAddress: addressUtils.generatePseudoRandomAddress(),
             makerAssetData: assetDataUtils.encodeERC20AssetData(addressUtils.generatePseudoRandomAddress()),
diff --git a/contracts/exchange/test/core.ts b/contracts/exchange/test/core.ts
index 82e27dcf5f..809f752297 100644
--- a/contracts/exchange/test/core.ts
+++ b/contracts/exchange/test/core.ts
@@ -33,7 +33,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, orderHashUtils } from '@0x/order-utils';
 import { RevertReason, SignatureType, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
 import { LogWithDecodedArgs } from 'ethereum-types';
@@ -55,6 +55,7 @@ const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 // tslint:disable:no-unnecessary-type-assertion
 describe('Exchange core', () => {
+    let chainId: number;
     let makerAddress: string;
     let owner: string;
     let takerAddress: string;
@@ -102,6 +103,7 @@ describe('Exchange core', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress] = _.slice(accounts, 0, 4));
 
@@ -136,6 +138,7 @@ describe('Exchange core', () => {
             provider,
             txDefaults,
             assetDataUtils.encodeERC20AssetData(zrxToken.address),
+            new BigNumber(chainId),
         );
         maliciousWallet = maliciousValidator = await TestStaticCallReceiverContract.deployFrom0xArtifactAsync(
             artifacts.TestStaticCallReceiver,
@@ -206,6 +209,7 @@ describe('Exchange core', () => {
         const defaultOrderParams = {
             ...constants.STATIC_ORDER_PARAMS,
             exchangeAddress: exchange.address,
+            chainId,
             makerAddress,
             feeRecipientAddress,
             makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
diff --git a/contracts/exchange/test/internal.ts b/contracts/exchange/test/internal.ts
index 7a1e12a7a1..f23fc0cbc2 100644
--- a/contracts/exchange/test/internal.ts
+++ b/contracts/exchange/test/internal.ts
@@ -12,7 +12,7 @@ import {
 } from '@0x/contracts-test-utils';
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { Order, RevertReason, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import * as chai from 'chai';
 import * as _ from 'lodash';
 
@@ -37,6 +37,7 @@ const emptyOrder: Order = {
     takerAssetData: '0x',
     salt: new BigNumber(0),
     exchangeAddress: constants.NULL_ADDRESS,
+    chainId: 0, // To be filled in later.
     feeRecipientAddress: constants.NULL_ADDRESS,
     expirationTimeSeconds: new BigNumber(0),
 };
@@ -49,6 +50,7 @@ const emptySignedOrder: SignedOrder = {
 const overflowErrorForCall = new Error(RevertReason.Uint256Overflow);
 
 describe('Exchange core internal functions', () => {
+    let chainId: number;
     let testExchange: TestExchangeInternalsContract;
     let overflowErrorForSendTransaction: Error | undefined;
     let divisionByZeroErrorForCall: Error | undefined;
@@ -61,10 +63,15 @@ describe('Exchange core internal functions', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
+        emptyOrder.chainId = chainId;
+        emptySignedOrder.chainId = chainId;
+
         testExchange = await TestExchangeInternalsContract.deployFrom0xArtifactAsync(
             artifacts.TestExchangeInternals,
             provider,
             txDefaults,
+            new BigNumber(chainId),
         );
         overflowErrorForSendTransaction = new Error(
             await getRevertReasonOrErrorMessageForSendTransactionAsync(RevertReason.Uint256Overflow),
diff --git a/contracts/exchange/test/match_orders.ts b/contracts/exchange/test/match_orders.ts
index 783adfe487..d6a25df97a 100644
--- a/contracts/exchange/test/match_orders.ts
+++ b/contracts/exchange/test/match_orders.ts
@@ -15,7 +15,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils } from '@0x/order-utils';
 import { RevertReason } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
 import * as _ from 'lodash';
@@ -34,6 +34,7 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe('matchOrders', () => {
+    let chainId: number;
     let makerAddressLeft: string;
     let makerAddressRight: string;
     let owner: string;
@@ -76,6 +77,8 @@ describe('matchOrders', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        // Get the chain ID.
+        chainId = await providerUtils.getChainIdAsync(provider);
         // Create accounts
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         // Hack(albrow): Both Prettier and TSLint insert a trailing comma below
@@ -119,6 +122,7 @@ describe('matchOrders', () => {
             provider,
             txDefaults,
             assetDataUtils.encodeERC20AssetData(zrxToken.address),
+            new BigNumber(chainId)
         );
         exchangeWrapper = new ExchangeWrapper(exchange, provider);
         await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
@@ -153,6 +157,7 @@ describe('matchOrders', () => {
             ...constants.STATIC_ORDER_PARAMS,
             makerAddress: makerAddressLeft,
             exchangeAddress: exchange.address,
+            chainId,
             makerAssetData: assetDataUtils.encodeERC20AssetData(defaultERC20MakerAssetAddress),
             takerAssetData: assetDataUtils.encodeERC20AssetData(defaultERC20TakerAssetAddress),
             feeRecipientAddress: feeRecipientAddressLeft,
@@ -161,6 +166,7 @@ describe('matchOrders', () => {
             ...constants.STATIC_ORDER_PARAMS,
             makerAddress: makerAddressRight,
             exchangeAddress: exchange.address,
+            chainId,
             makerAssetData: assetDataUtils.encodeERC20AssetData(defaultERC20TakerAssetAddress),
             takerAssetData: assetDataUtils.encodeERC20AssetData(defaultERC20MakerAssetAddress),
             feeRecipientAddress: feeRecipientAddressRight,
@@ -175,6 +181,7 @@ describe('matchOrders', () => {
             artifacts.TestExchangeInternals,
             provider,
             txDefaults,
+            new BigNumber(chainId),
         );
     });
     beforeEach(async () => {
diff --git a/contracts/exchange/test/signature_validator.ts b/contracts/exchange/test/signature_validator.ts
index 33510e50c0..b84edf9686 100644
--- a/contracts/exchange/test/signature_validator.ts
+++ b/contracts/exchange/test/signature_validator.ts
@@ -12,6 +12,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, orderHashUtils, signatureUtils } from '@0x/order-utils';
 import { RevertReason, SignatureType, SignedOrder } from '@0x/types';
+import { BigNumber, providerUtils } from '@0x/utils';
 import * as chai from 'chai';
 import { LogWithDecodedArgs } from 'ethereum-types';
 import ethUtil = require('ethereumjs-util');
@@ -31,6 +32,7 @@ const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 // tslint:disable:no-unnecessary-type-assertion
 describe('MixinSignatureValidator', () => {
+    let chainId: number;
     let signedOrder: SignedOrder;
     let orderFactory: OrderFactory;
     let signatureValidator: TestSignatureValidatorContract;
@@ -51,6 +53,7 @@ describe('MixinSignatureValidator', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         const makerAddress = accounts[0];
         signerAddress = makerAddress;
@@ -59,6 +62,7 @@ describe('MixinSignatureValidator', () => {
             artifacts.TestSignatureValidator,
             provider,
             txDefaults,
+            new BigNumber(chainId),
         );
         testWallet = await WalletContract.deployFrom0xArtifactAsync(
             artifacts.Wallet,
@@ -98,6 +102,7 @@ describe('MixinSignatureValidator', () => {
         const defaultOrderParams = {
             ...constants.STATIC_ORDER_PARAMS,
             exchangeAddress: signatureValidator.address,
+            chainId,
             makerAddress,
             feeRecipientAddress: addressUtils.generatePseudoRandomAddress(),
             makerAssetData: assetDataUtils.encodeERC20AssetData(addressUtils.generatePseudoRandomAddress()),
diff --git a/contracts/exchange/test/transactions.ts b/contracts/exchange/test/transactions.ts
index 4f8c075794..784e640a7f 100644
--- a/contracts/exchange/test/transactions.ts
+++ b/contracts/exchange/test/transactions.ts
@@ -15,7 +15,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, generatePseudoRandomSalt } from '@0x/order-utils';
 import { OrderWithoutExchangeAddress, RevertReason, SignedOrder, SignedZeroExTransaction } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import * as chai from 'chai';
 import * as _ from 'lodash';
 
@@ -26,6 +26,7 @@ const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 
 describe('Exchange transactions', () => {
+    let chainId: number;
     let senderAddress: string;
     let owner: string;
     let makerAddress: string;
@@ -66,6 +67,7 @@ describe('Exchange transactions', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         const usedAddresses = ([owner, senderAddress, makerAddress, takerAddress, feeRecipientAddress] = _.slice(
             accounts,
@@ -88,6 +90,7 @@ describe('Exchange transactions', () => {
             provider,
             txDefaults,
             assetDataUtils.encodeERC20AssetData(zrxToken.address),
+            new BigNumber(chainId)
         );
         exchangeWrapper = new ExchangeWrapper(exchange, provider);
         await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
@@ -104,6 +107,7 @@ describe('Exchange transactions', () => {
             ...constants.STATIC_ORDER_PARAMS,
             senderAddress,
             exchangeAddress: exchange.address,
+            chainId,
             makerAddress,
             feeRecipientAddress,
             makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerTokenAddress),
@@ -112,8 +116,16 @@ describe('Exchange transactions', () => {
         makerPrivateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddress)];
         takerPrivateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(takerAddress)];
         orderFactory = new OrderFactory(makerPrivateKey, defaultOrderParams);
-        makerTransactionFactory = new TransactionFactory(makerPrivateKey, exchange.address);
-        takerTransactionFactory = new TransactionFactory(takerPrivateKey, exchange.address);
+        makerTransactionFactory = new TransactionFactory(
+            makerPrivateKey,
+            exchange.address,
+            chainId,
+        );
+        takerTransactionFactory = new TransactionFactory(
+            takerPrivateKey,
+            exchange.address,
+            chainId,
+        );
     });
     describe('executeTransaction', () => {
         describe('fillOrder', () => {
@@ -346,6 +358,7 @@ describe('Exchange transactions', () => {
                 ...constants.STATIC_ORDER_PARAMS,
                 senderAddress: whitelist.address,
                 exchangeAddress: exchange.address,
+                chainId,
                 makerAddress,
                 feeRecipientAddress,
                 makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerTokenAddress),
diff --git a/contracts/exchange/test/utils/fill_order_combinatorial_utils.ts b/contracts/exchange/test/utils/fill_order_combinatorial_utils.ts
index a15b27e12b..d5e1c912e3 100644
--- a/contracts/exchange/test/utils/fill_order_combinatorial_utils.ts
+++ b/contracts/exchange/test/utils/fill_order_combinatorial_utils.ts
@@ -63,6 +63,7 @@ export async function fillOrderCombinatorialUtilsFactoryAsync(
 
     const supportedProvider = web3Wrapper.getProvider();
     const provider = providerUtils.standardizeOrThrow(supportedProvider);
+    const chainId = await providerUtils.getChainIdAsync(provider);
     const erc20Wrapper = new ERC20Wrapper(provider, userAddresses, ownerAddress);
     const erc721Wrapper = new ERC721Wrapper(provider, userAddresses, ownerAddress);
 
@@ -102,6 +103,7 @@ export async function fillOrderCombinatorialUtilsFactoryAsync(
         provider,
         txDefaults,
         zrxAssetData,
+        new BigNumber(chainId)
     );
     const exchangeWrapper = new ExchangeWrapper(exchangeContract, provider);
     await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, ownerAddress);
@@ -129,12 +131,14 @@ export async function fillOrderCombinatorialUtilsFactoryAsync(
         erc721Token,
         erc721Balances,
         exchangeContract.address,
+        chainId
     );
 
     const testLibsContract = await TestLibsContract.deployFrom0xArtifactAsync(
         libsArtifacts.TestLibs,
         provider,
         txDefaults,
+        new BigNumber(chainId),
     );
 
     const fillOrderCombinatorialUtils = new FillOrderCombinatorialUtils(
@@ -404,7 +408,6 @@ export class FillOrderCombinatorialUtils {
         try {
             await orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
                 exchangeTransferSimulator,
-                provider,
                 signedOrder,
                 takerAssetFillAmount,
                 this.takerAddress,
@@ -627,7 +630,11 @@ export class FillOrderCombinatorialUtils {
         balanceAndProxyAllowanceFetcher: SimpleAssetBalanceAndProxyAllowanceFetcher,
         orderFilledCancelledFetcher: SimpleOrderFilledCancelledFetcher,
     ): Promise<BigNumber> {
-        const orderStateUtils = new OrderStateUtils(balanceAndProxyAllowanceFetcher, orderFilledCancelledFetcher);
+        const orderStateUtils = new OrderStateUtils(
+            balanceAndProxyAllowanceFetcher,
+            orderFilledCancelledFetcher,
+            signedOrder.chainId,
+        );
         const fillableTakerAssetAmount = await orderStateUtils.getMaxFillableTakerAssetAmountAsync(
             signedOrder,
             this.takerAddress,
diff --git a/contracts/exchange/test/utils/order_factory_from_scenario.ts b/contracts/exchange/test/utils/order_factory_from_scenario.ts
index 6f56459060..4417f71a7f 100644
--- a/contracts/exchange/test/utils/order_factory_from_scenario.ts
+++ b/contracts/exchange/test/utils/order_factory_from_scenario.ts
@@ -32,6 +32,7 @@ export class OrderFactoryFromScenario {
     private readonly _erc721Token: DummyERC721TokenContract;
     private readonly _erc721Balances: ERC721TokenIdsByOwner;
     private readonly _exchangeAddress: string;
+    private readonly _chainId: number;
     constructor(
         userAddresses: string[],
         zrxAddress: string,
@@ -41,6 +42,7 @@ export class OrderFactoryFromScenario {
         erc721Token: DummyERC721TokenContract,
         erc721Balances: ERC721TokenIdsByOwner,
         exchangeAddress: string,
+        chainId: number
     ) {
         this._userAddresses = userAddresses;
         this._zrxAddress = zrxAddress;
@@ -50,6 +52,7 @@ export class OrderFactoryFromScenario {
         this._erc721Token = erc721Token;
         this._erc721Balances = erc721Balances;
         this._exchangeAddress = exchangeAddress;
+        this._chainId = chainId;
     }
     public generateOrder(orderScenario: OrderScenario): Order {
         const makerAddress = this._userAddresses[1];
@@ -285,6 +288,7 @@ export class OrderFactoryFromScenario {
             takerAssetData,
             salt: generatePseudoRandomSalt(),
             exchangeAddress: this._exchangeAddress,
+            chainId: this._chainId,
             feeRecipientAddress,
             expirationTimeSeconds,
         };
diff --git a/contracts/exchange/test/wrapper.ts b/contracts/exchange/test/wrapper.ts
index 8a86f51307..ecfa568db5 100644
--- a/contracts/exchange/test/wrapper.ts
+++ b/contracts/exchange/test/wrapper.ts
@@ -17,7 +17,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, orderHashUtils } from '@0x/order-utils';
 import { RevertReason, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
 import * as _ from 'lodash';
@@ -29,6 +29,7 @@ const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 
 describe('Exchange wrappers', () => {
+    let chainId: number;
     let makerAddress: string;
     let owner: string;
     let takerAddress: string;
@@ -62,6 +63,7 @@ describe('Exchange wrappers', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress] = _.slice(accounts, 0, 4));
 
@@ -88,6 +90,7 @@ describe('Exchange wrappers', () => {
             provider,
             txDefaults,
             assetDataUtils.encodeERC20AssetData(zrxToken.address),
+            new BigNumber(chainId)
         );
         exchangeWrapper = new ExchangeWrapper(exchange, provider);
         await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
@@ -119,6 +122,7 @@ describe('Exchange wrappers', () => {
         const defaultOrderParams = {
             ...constants.STATIC_ORDER_PARAMS,
             exchangeAddress: exchange.address,
+            chainId,
             makerAddress,
             feeRecipientAddress,
             makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
diff --git a/contracts/extensions/test/balance_threshold_filter.ts b/contracts/extensions/test/balance_threshold_filter.ts
index 530eefd51b..be669c871b 100644
--- a/contracts/extensions/test/balance_threshold_filter.ts
+++ b/contracts/extensions/test/balance_threshold_filter.ts
@@ -2,7 +2,7 @@ import { ExchangeContract, ExchangeWrapper } from '@0x/contracts-exchange';
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils } from '@0x/order-utils';
 import { Order, RevertReason, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
 import { TransactionReceiptWithDecodedLogs } from 'ethereum-types';
@@ -40,6 +40,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
     const makerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(1000), DECIMALS_DEFAULT);
     const takerAssetFillAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(250), DECIMALS_DEFAULT);
 
+    let chainId: number;
     let validMakerAddress: string;
     let validMakerAddress2: string;
     let owner: string;
@@ -88,6 +89,8 @@ describe(ContractName.BalanceThresholdFilter, () => {
     };
 
     before(async () => {
+        // Get the chain ID.
+        chainId = await providerUtils.getChainIdAsync(provider);
         // Create accounts
         await blockchainLifecycle.startAsync();
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
@@ -131,6 +134,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
             provider,
             txDefaults,
             zrxAssetData,
+            new BigNumber(chainId),
         );
         exchangeWrapper = new ExchangeWrapper(exchangeInstance, provider);
         // Register proxies
@@ -164,6 +168,7 @@ describe(ContractName.BalanceThresholdFilter, () => {
         // Default order parameters
         defaultOrderParams = {
             exchangeAddress: exchangeInstance.address,
+            chainId,
             feeRecipientAddress,
             makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
             takerAssetData: assetDataUtils.encodeERC20AssetData(defaultTakerAssetAddress),
@@ -197,25 +202,25 @@ describe(ContractName.BalanceThresholdFilter, () => {
         erc20TakerBalanceThresholdWrapper = new BalanceThresholdWrapper(
             erc20BalanceThresholdFilterInstance,
             exchangeInstance,
-            new TransactionFactory(takerPrivateKey, exchangeInstance.address),
+            new TransactionFactory(takerPrivateKey, exchangeInstance.address, chainId),
             provider,
         );
         erc721TakerBalanceThresholdWrapper = new BalanceThresholdWrapper(
             erc721BalanceThresholdFilterInstance,
             exchangeInstance,
-            new TransactionFactory(takerPrivateKey, exchangeInstance.address),
+            new TransactionFactory(takerPrivateKey, exchangeInstance.address, chainId),
             provider,
         );
         erc721MakerBalanceThresholdWrapper = new BalanceThresholdWrapper(
             erc721BalanceThresholdFilterInstance,
             exchangeInstance,
-            new TransactionFactory(makerPrivateKey, exchangeInstance.address),
+            new TransactionFactory(makerPrivateKey, exchangeInstance.address, chainId),
             provider,
         );
         erc721NonValidBalanceThresholdWrapper = new BalanceThresholdWrapper(
             erc721BalanceThresholdFilterInstance,
             exchangeInstance,
-            new TransactionFactory(invalidAddressPrivateKey, exchangeInstance.address),
+            new TransactionFactory(invalidAddressPrivateKey, exchangeInstance.address, chainId),
             provider,
         );
     });
diff --git a/contracts/extensions/test/dutch_auction.ts b/contracts/extensions/test/dutch_auction.ts
index 639f61999d..47788cb303 100644
--- a/contracts/extensions/test/dutch_auction.ts
+++ b/contracts/extensions/test/dutch_auction.ts
@@ -18,7 +18,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, generatePseudoRandomSalt } from '@0x/order-utils';
 import { RevertReason, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
 import * as _ from 'lodash';
@@ -31,6 +31,7 @@ const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 const DECIMALS_DEFAULT = 18;
 
 describe(ContractName.DutchAuction, () => {
+    let chainId: number;
     let makerAddress: string;
     let owner: string;
     let takerAddress: string;
@@ -62,6 +63,8 @@ describe(ContractName.DutchAuction, () => {
 
     before(async () => {
         await blockchainLifecycle.startAsync();
+
+        chainId = await providerUtils.getChainIdAsync(provider);
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress] = accounts);
 
@@ -91,6 +94,7 @@ describe(ContractName.DutchAuction, () => {
             provider,
             txDefaults,
             zrxAssetData,
+            new BigNumber(chainId),
         );
         const exchangeWrapper = new ExchangeWrapper(exchangeInstance, provider);
         await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
@@ -145,6 +149,7 @@ describe(ContractName.DutchAuction, () => {
         const sellerDefaultOrderParams = {
             salt: generatePseudoRandomSalt(),
             exchangeAddress: exchangeInstance.address,
+            chainId,
             makerAddress,
             feeRecipientAddress,
             // taker address or sender address should be set to the ducth auction contract
diff --git a/contracts/extensions/test/order_matcher.ts b/contracts/extensions/test/order_matcher.ts
index 99ec0d06d9..04ad9b3e2d 100644
--- a/contracts/extensions/test/order_matcher.ts
+++ b/contracts/extensions/test/order_matcher.ts
@@ -23,7 +23,7 @@ import {
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils } from '@0x/order-utils';
 import { RevertReason } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
 import { LogWithDecodedArgs } from 'ethereum-types';
@@ -36,6 +36,7 @@ chaiSetup.configure();
 const expect = chai.expect;
 // tslint:disable:no-unnecessary-type-assertion
 describe('OrderMatcher', () => {
+    let chainId: number;
     let makerAddressLeft: string;
     let makerAddressRight: string;
     let owner: string;
@@ -69,6 +70,7 @@ describe('OrderMatcher', () => {
         await blockchainLifecycle.revertAsync();
     });
     before(async () => {
+        chainId = await providerUtils.getChainIdAsync(provider);
         // Create accounts
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         // Hack(albrow): Both Prettier and TSLint insert a trailing comma below
@@ -110,6 +112,7 @@ describe('OrderMatcher', () => {
             provider,
             txDefaults,
             assetDataUtils.encodeERC20AssetData(zrxToken.address),
+            new BigNumber(chainId),
         );
         exchangeWrapper = new ExchangeWrapper(exchange, provider);
         await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
@@ -165,6 +168,7 @@ describe('OrderMatcher', () => {
             ...constants.STATIC_ORDER_PARAMS,
             makerAddress: makerAddressLeft,
             exchangeAddress: exchange.address,
+            chainId,
             makerAssetData: leftMakerAssetData,
             takerAssetData: leftTakerAssetData,
             feeRecipientAddress: feeRecipientAddressLeft,
@@ -175,6 +179,7 @@ describe('OrderMatcher', () => {
             ...constants.STATIC_ORDER_PARAMS,
             makerAddress: makerAddressRight,
             exchangeAddress: exchange.address,
+            chainId,
             makerAssetData: leftTakerAssetData,
             takerAssetData: leftMakerAssetData,
             feeRecipientAddress: feeRecipientAddressRight,
@@ -199,6 +204,7 @@ describe('OrderMatcher', () => {
                 provider,
                 txDefaults,
                 constants.NULL_BYTES,
+                new BigNumber(chainId),
             );
             return expectContractCreationFailedAsync(
                 (OrderMatcherContract.deployFrom0xArtifactAsync(
diff --git a/contracts/test-utils/src/transaction_factory.ts b/contracts/test-utils/src/transaction_factory.ts
index e6cd4c23f6..0dc52e4634 100644
--- a/contracts/test-utils/src/transaction_factory.ts
+++ b/contracts/test-utils/src/transaction_factory.ts
@@ -8,9 +8,12 @@ export class TransactionFactory {
     private readonly _signerBuff: Buffer;
     private readonly _exchangeAddress: string;
     private readonly _privateKey: Buffer;
-    constructor(privateKey: Buffer, exchangeAddress: string) {
+    private readonly _chainId: number;
+
+    constructor(privateKey: Buffer, exchangeAddress: string, chainId: number) {
         this._privateKey = privateKey;
         this._exchangeAddress = exchangeAddress;
+        this._chainId = chainId;
         this._signerBuff = ethUtil.privateToAddress(this._privateKey);
     }
     public newSignedTransaction(
@@ -24,6 +27,7 @@ export class TransactionFactory {
             signerAddress,
             data,
             verifyingContractAddress: this._exchangeAddress,
+            chainId: this._chainId,
         };
 
         const transactionHashBuffer = transactionHashUtils.getTransactionHashBuffer(transaction);
diff --git a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
index a3b26a9724..6c647b9cf2 100644
--- a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
@@ -11,7 +11,7 @@ import {
     OrderValidationUtils,
 } from '@0x/order-utils';
 import { AssetProxyId, Order, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import { BlockParamLiteral, ContractAbi, LogWithDecodedArgs } from 'ethereum-types';
 import * as _ from 'lodash';
@@ -1239,7 +1239,6 @@ export class ExchangeWrapper extends ContractWrapper {
         const orderValidationUtils = new OrderValidationUtils(filledCancelledFetcher, this._web3Wrapper.getProvider());
         await orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
             exchangeTradeSimulator,
-            this._web3Wrapper.getProvider(),
             signedOrder,
             fillTakerAssetAmount,
             takerAddress,
@@ -1260,8 +1259,9 @@ export class ExchangeWrapper extends ContractWrapper {
      * @return TransactionEncoder
      */
     public async transactionEncoderAsync(): Promise<TransactionEncoder> {
+        const chainId = await providerUtils.getChainIdAsync(this._web3Wrapper.getProvider());
         const exchangeInstance = await this._getExchangeContractAsync();
-        const encoder = new TransactionEncoder(exchangeInstance);
+        const encoder = new TransactionEncoder(exchangeInstance, chainId);
         return encoder;
     }
     // tslint:enable:no-unused-variable
diff --git a/packages/contract-wrappers/src/utils/transaction_encoder.ts b/packages/contract-wrappers/src/utils/transaction_encoder.ts
index 0832ee73a9..fec9e0a028 100644
--- a/packages/contract-wrappers/src/utils/transaction_encoder.ts
+++ b/packages/contract-wrappers/src/utils/transaction_encoder.ts
@@ -15,8 +15,11 @@ import { assert } from './assert';
  */
 export class TransactionEncoder {
     private readonly _exchangeInstance: ExchangeContract;
-    constructor(exchangeInstance: ExchangeContract) {
+    private readonly _chainId: number;
+
+    constructor(exchangeInstance: ExchangeContract, chainId: number) {
         this._exchangeInstance = exchangeInstance;
+        this._chainId = chainId;
     }
     /**
      * Hashes the transaction data for use with the Exchange contract.
@@ -29,6 +32,7 @@ export class TransactionEncoder {
         const exchangeAddress = this._getExchangeContract().address;
         const transaction = {
             verifyingContractAddress: exchangeAddress,
+            chainId: this._chainId,
             salt,
             signerAddress,
             data,
diff --git a/packages/contract-wrappers/test/calldata_optimization_utils_test.ts b/packages/contract-wrappers/test/calldata_optimization_utils_test.ts
index 6cb8a669e3..70430ed81c 100644
--- a/packages/contract-wrappers/test/calldata_optimization_utils_test.ts
+++ b/packages/contract-wrappers/test/calldata_optimization_utils_test.ts
@@ -14,8 +14,9 @@ const expect = chai.expect;
 // utility for generating a set of order objects with mostly NULL values
 // except for a specified makerAssetData and takerAssetData
 const FAKE_ORDERS_COUNT = 5;
+const CHAIN_ID = 1337;
 const generateFakeOrders = (makerAssetData: string, takerAssetData: string) =>
-    _.map(_.range(FAKE_ORDERS_COUNT), index => {
+    _.map(_.range(FAKE_ORDERS_COUNT), () => {
         const order = orderFactory.createOrder(
             constants.NULL_ADDRESS,
             constants.ZERO_AMOUNT,
@@ -23,6 +24,7 @@ const generateFakeOrders = (makerAssetData: string, takerAssetData: string) =>
             constants.ZERO_AMOUNT,
             takerAssetData,
             constants.NULL_ADDRESS,
+            CHAIN_ID,
         );
         return {
             ...order,
diff --git a/packages/order-utils/src/constants.ts b/packages/order-utils/src/constants.ts
index 278b343a8c..8aa03ad8b9 100644
--- a/packages/order-utils/src/constants.ts
+++ b/packages/order-utils/src/constants.ts
@@ -136,7 +136,7 @@ export const constants = {
         ],
     },
     COORDINATOR_DOMAIN_NAME: '0x Protocol Coordinator',
-    COORDINATOR_DOMAIN_VERSION: '1.0.0',
+    COORDINATOR_DOMAIN_VERSION: '2.0.0',
     COORDINATOR_APPROVAL_SCHEMA: {
         name: 'CoordinatorApproval',
         parameters: [
diff --git a/packages/order-utils/src/eip712_utils.ts b/packages/order-utils/src/eip712_utils.ts
index 927dab0733..17f95ce52c 100644
--- a/packages/order-utils/src/eip712_utils.ts
+++ b/packages/order-utils/src/eip712_utils.ts
@@ -61,6 +61,7 @@ export const eip712Utils = {
         });
         const domain = {
             verifyingContractAddress: order.exchangeAddress,
+            chainId: order.chainId,
         };
         const typedData = eip712Utils.createTypedData(
             constants.EXCHANGE_ORDER_SCHEMA.name,
@@ -84,6 +85,7 @@ export const eip712Utils = {
         });
         const domain = {
             verifyingContractAddress: zeroExTransaction.verifyingContractAddress,
+            chainId: zeroExTransaction.chainId,
         };
         const typedData = eip712Utils.createTypedData(
             constants.EXCHANGE_ZEROEX_TRANSACTION_SCHEMA.name,
diff --git a/packages/order-utils/src/order_factory.ts b/packages/order-utils/src/order_factory.ts
index 61da6bacd3..28d6d97730 100644
--- a/packages/order-utils/src/order_factory.ts
+++ b/packages/order-utils/src/order_factory.ts
@@ -1,5 +1,5 @@
 import { Order, SignedOrder } from '@0x/types';
-import { BigNumber } from '@0x/utils';
+import { BigNumber, providerUtils } from '@0x/utils';
 import { SupportedProvider } from 'ethereum-types';
 import * as _ from 'lodash';
 
@@ -10,14 +10,18 @@ import { signatureUtils } from './signature_utils';
 import { CreateOrderOpts } from './types';
 export const orderFactory = {
     createOrderFromPartial(partialOrder: Partial<Order>): Order {
-        const defaultOrder = generateEmptyOrder();
+        if (_.isNil(partialOrder.chainId))
+            throw new Error('chainId must be valid');
+        const defaultOrder = generateEmptyOrder(partialOrder.chainId);
         return {
             ...defaultOrder,
             ...partialOrder,
         };
     },
     createSignedOrderFromPartial(partialSignedOrder: Partial<SignedOrder>): SignedOrder {
-        const defaultOrder = generateEmptySignedOrder();
+        if (_.isNil(partialSignedOrder.chainId))
+            throw new Error('chainId must be valid');
+        const defaultOrder = generateEmptySignedOrder(partialSignedOrder.chainId);
         return {
             ...defaultOrder,
             ...partialSignedOrder,
@@ -30,6 +34,7 @@ export const orderFactory = {
         takerAssetAmount: BigNumber,
         takerAssetData: string,
         exchangeAddress: string,
+        chainId: number,
         createOrderOpts: CreateOrderOpts = generateDefaultCreateOrderOpts(),
     ): Order {
         const defaultCreateOrderOpts = generateDefaultCreateOrderOpts();
@@ -48,6 +53,7 @@ export const orderFactory = {
             salt: createOrderOpts.salt || defaultCreateOrderOpts.salt,
             expirationTimeSeconds:
                 createOrderOpts.expirationTimeSeconds || defaultCreateOrderOpts.expirationTimeSeconds,
+            chainId: chainId,
         };
         return order;
     },
@@ -68,6 +74,7 @@ export const orderFactory = {
             takerAssetAmount,
             takerAssetData,
             exchangeAddress,
+            await providerUtils.getChainIdAsync(supportedProvider),
             createOrderOpts,
         );
         const orderHash = orderHashUtils.getOrderHashHex(order);
@@ -77,13 +84,13 @@ export const orderFactory = {
     },
 };
 
-function generateEmptySignedOrder(): SignedOrder {
+function generateEmptySignedOrder(chainId: number): SignedOrder {
     return {
-        ...generateEmptyOrder(),
+        ...generateEmptyOrder(chainId),
         signature: constants.NULL_BYTES,
     };
 }
-function generateEmptyOrder(): Order {
+function generateEmptyOrder(chainId: number): Order {
     return {
         senderAddress: constants.NULL_ADDRESS,
         makerAddress: constants.NULL_ADDRESS,
@@ -96,6 +103,7 @@ function generateEmptyOrder(): Order {
         takerAssetData: constants.NULL_BYTES,
         salt: generatePseudoRandomSalt(),
         exchangeAddress: constants.NULL_ADDRESS,
+        chainId: chainId,
         feeRecipientAddress: constants.NULL_ADDRESS,
         expirationTimeSeconds: constants.INFINITE_TIMESTAMP_SEC,
     };
diff --git a/packages/order-utils/src/order_state_utils.ts b/packages/order-utils/src/order_state_utils.ts
index ad8b65cc78..0b9b0d0041 100644
--- a/packages/order-utils/src/order_state_utils.ts
+++ b/packages/order-utils/src/order_state_utils.ts
@@ -42,6 +42,7 @@ type OrderValidationResult = OrderValidResult | OrderInvalidResult;
 export class OrderStateUtils {
     private readonly _balanceAndProxyAllowanceFetcher: AbstractBalanceAndProxyAllowanceFetcher;
     private readonly _orderFilledCancelledFetcher: AbstractOrderFilledCancelledFetcher;
+    private readonly _chainId: number;
     private static _validateIfOrderIsValid(
         signedOrder: SignedOrder,
         sidedOrderRelevantState: SidedOrderRelevantState,
@@ -102,14 +103,17 @@ export class OrderStateUtils {
      * and proxyAllowances for Ethereum addresses. It must implement AbstractBalanceAndProxyAllowanceFetcher
      * @param orderFilledCancelledFetcher A class that is capable of fetching whether an order
      * is cancelled and how much of it has been filled. It must implement AbstractOrderFilledCancelledFetcher
+     * @param chainId The chain ID of the network being used.
      * @return Instance of OrderStateUtils
      */
     constructor(
         balanceAndProxyAllowanceFetcher: AbstractBalanceAndProxyAllowanceFetcher,
         orderFilledCancelledFetcher: AbstractOrderFilledCancelledFetcher,
+        chainId: number,
     ) {
         this._balanceAndProxyAllowanceFetcher = balanceAndProxyAllowanceFetcher;
         this._orderFilledCancelledFetcher = orderFilledCancelledFetcher;
+        this._chainId = chainId;
     }
     /**
      * Get the orderState for an "open" order (i.e where takerAddress=NULL_ADDRESS)
diff --git a/packages/order-utils/src/order_validation_utils.ts b/packages/order-utils/src/order_validation_utils.ts
index 1949155b6a..860d37683e 100644
--- a/packages/order-utils/src/order_validation_utils.ts
+++ b/packages/order-utils/src/order_validation_utils.ts
@@ -227,7 +227,6 @@ export class OrderValidationUtils {
     /**
      * Validate a call to FillOrder and throw if it wouldn't succeed
      * @param exchangeTradeEmulator ExchangeTradeEmulator to use
-     * @param supportedProvider Web3 provider to use for JSON RPC requests
      * @param signedOrder SignedOrder of interest
      * @param fillTakerAssetAmount Amount we'd like to fill the order for
      * @param takerAddress The taker of the order
@@ -235,7 +234,6 @@ export class OrderValidationUtils {
      */
     public async validateFillOrderThrowIfInvalidAsync(
         exchangeTradeEmulator: ExchangeTransferSimulator,
-        supportedProvider: SupportedProvider,
         signedOrder: SignedOrder,
         fillTakerAssetAmount: BigNumber,
         takerAddress: string,
@@ -247,10 +245,10 @@ export class OrderValidationUtils {
         if (fillTakerAssetAmount.eq(0)) {
             throw new Error(RevertReason.InvalidTakerAmount);
         }
-        const provider = providerUtils.standardizeOrThrow(supportedProvider);
+
         const orderHash = orderHashUtils.getOrderHashHex(signedOrder);
         const isValid = await signatureUtils.isValidSignatureAsync(
-            provider,
+            this._provider,
             orderHash,
             signedOrder.signature,
             signedOrder.makerAddress,
diff --git a/packages/order-utils/src/signature_utils.ts b/packages/order-utils/src/signature_utils.ts
index a7d15af313..35aafa1446 100644
--- a/packages/order-utils/src/signature_utils.ts
+++ b/packages/order-utils/src/signature_utils.ts
@@ -232,6 +232,7 @@ export const signatureUtils = {
             if (err.message.includes('User denied message signature')) {
                 throw err;
             }
+            const chainId = await providerUtils.getChainIdAsync(supportedProvider);
             const orderHash = orderHashUtils.getOrderHashHex(order);
             const signatureHex = await signatureUtils.ecSignHashAsync(supportedProvider, orderHash, signerAddress);
             const signedOrder = {
@@ -255,6 +256,7 @@ export const signatureUtils = {
         signerAddress: string,
     ): Promise<SignedOrder> {
         const provider = providerUtils.standardizeOrThrow(supportedProvider);
+        const chainId = await providerUtils.getChainIdAsync(provider);
         assert.isETHAddressHex('signerAddress', signerAddress);
         assert.doesConformToSchema('order', order, schemas.orderSchema, [schemas.hexSchema]);
         const web3Wrapper = new Web3Wrapper(provider);
diff --git a/packages/order-utils/test/eip712_utils_test.ts b/packages/order-utils/test/eip712_utils_test.ts
index c97bed1447..6ff8febfc5 100644
--- a/packages/order-utils/test/eip712_utils_test.ts
+++ b/packages/order-utils/test/eip712_utils_test.ts
@@ -11,6 +11,8 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe('EIP712 Utils', () => {
+    const CHAIN_ID = 1337;
+
     describe('createTypedData', () => {
         it('adds in the EIP712DomainSeparator with default values', () => {
             const primaryType = 'Test';
@@ -18,7 +20,7 @@ describe('EIP712 Utils', () => {
                 primaryType,
                 { Test: [{ name: 'testValue', type: 'uint256' }] },
                 { testValue: '1' },
-                { verifyingContractAddress: constants.NULL_ADDRESS },
+                { chainId: CHAIN_ID, verifyingContractAddress: constants.NULL_ADDRESS, },
             );
             expect(typedData.domain).to.not.be.undefined();
             expect(typedData.types.EIP712Domain).to.not.be.undefined();
@@ -36,7 +38,12 @@ describe('EIP712 Utils', () => {
                 primaryType,
                 { Test: [{ name: 'testValue', type: 'uint256' }] },
                 { testValue: '1' },
-                { name: domainName, version: domainVersion, verifyingContractAddress: constants.NULL_ADDRESS },
+                {
+                    name: domainName,
+                    version: domainVersion,
+                    chainId: CHAIN_ID,
+                    verifyingContractAddress: constants.NULL_ADDRESS,
+                },
             );
             expect(typedData.domain).to.not.be.undefined();
             expect(typedData.types.EIP712Domain).to.not.be.undefined();
@@ -54,6 +61,7 @@ describe('EIP712 Utils', () => {
                 data: constants.NULL_BYTES,
                 signerAddress: constants.NULL_ADDRESS,
                 verifyingContractAddress: constants.NULL_ADDRESS,
+                chainId: CHAIN_ID,
             });
             expect(typedData.primaryType).to.eq(constants.EXCHANGE_ZEROEX_TRANSACTION_SCHEMA.name);
             expect(typedData.types.EIP712Domain).to.not.be.undefined();
diff --git a/packages/order-utils/test/order_hash_test.ts b/packages/order-utils/test/order_hash_test.ts
index 514fc27099..a4c7de2d9a 100644
--- a/packages/order-utils/test/order_hash_test.ts
+++ b/packages/order-utils/test/order_hash_test.ts
@@ -14,8 +14,9 @@ const expect = chai.expect;
 
 describe('Order hashing', () => {
     describe('#getOrderHashHex', () => {
-        const expectedOrderHash = '0x434c6b41e2fb6dfcfe1b45c4492fb03700798e9c1afc6f801ba6203f948c1fa7';
+        const expectedOrderHash = '0x2af69ce573fc9ffc734c88aaafc6907e2619572a462ca1ab2326e0e4bebec127';
         const fakeExchangeContractAddress = '0x1dc4c1cefef38a777b15aa20260a54e584b16c48';
+        const fakeChainID = 1337;
         const order: Order = {
             makerAddress: constants.NULL_ADDRESS,
             takerAddress: constants.NULL_ADDRESS,
@@ -24,6 +25,7 @@ describe('Order hashing', () => {
             makerAssetData: constants.NULL_ADDRESS,
             takerAssetData: constants.NULL_ADDRESS,
             exchangeAddress: fakeExchangeContractAddress,
+            chainId: fakeChainID,
             salt: new BigNumber(0),
             makerFee: new BigNumber(0),
             takerFee: new BigNumber(0),
diff --git a/packages/order-utils/test/order_state_utils_test.ts b/packages/order-utils/test/order_state_utils_test.ts
index 42acd54c6f..b5fbd6f87f 100644
--- a/packages/order-utils/test/order_state_utils_test.ts
+++ b/packages/order-utils/test/order_state_utils_test.ts
@@ -14,6 +14,8 @@ chaiSetup.configure();
 const expect = chai.expect;
 
 describe('OrderStateUtils', () => {
+    const CHAIN_ID = 1337;
+
     describe('#getOpenOrderStateAsync', () => {
         const buildMockBalanceFetcher = (takerBalance: BigNumber): AbstractBalanceAndProxyAllowanceFetcher => {
             const balanceFetcher = {
@@ -58,7 +60,11 @@ describe('OrderStateUtils', () => {
                 1,
             );
 
-            const orderStateUtils = new OrderStateUtils(mockBalanceFetcher, mockOrderFilledFetcher);
+            const orderStateUtils = new OrderStateUtils(
+                mockBalanceFetcher,
+                mockOrderFilledFetcher,
+                CHAIN_ID,
+            );
             const orderState = await orderStateUtils.getOpenOrderStateAsync(signedOrder);
             expect(orderState.isValid).to.eq(true);
         });
@@ -77,7 +83,11 @@ describe('OrderStateUtils', () => {
                 1,
             );
 
-            const orderStateUtils = new OrderStateUtils(mockBalanceFetcher, mockOrderFilledFetcher);
+            const orderStateUtils = new OrderStateUtils(
+                mockBalanceFetcher,
+                mockOrderFilledFetcher,
+                CHAIN_ID,
+            );
             const orderState = await orderStateUtils.getOpenOrderStateAsync(signedOrder);
             expect(orderState.isValid).to.eq(false);
         });
@@ -97,7 +107,11 @@ describe('OrderStateUtils', () => {
                 1,
             );
 
-            const orderStateUtils = new OrderStateUtils(mockBalanceFetcher, mockOrderFilledFetcher);
+            const orderStateUtils = new OrderStateUtils(
+                mockBalanceFetcher,
+                mockOrderFilledFetcher,
+                CHAIN_ID,
+            );
             const orderState = await orderStateUtils.getOpenOrderStateAsync(signedOrder);
             expect(orderState.isValid).to.eq(false);
         });
@@ -117,7 +131,11 @@ describe('OrderStateUtils', () => {
                 1,
             );
 
-            const orderStateUtils = new OrderStateUtils(mockBalanceFetcher, mockOrderFilledFetcher);
+            const orderStateUtils = new OrderStateUtils(
+                mockBalanceFetcher,
+                mockOrderFilledFetcher,
+                CHAIN_ID,
+            );
             const orderState = await orderStateUtils.getOpenOrderStateAsync(signedOrder);
             expect(orderState.isValid).to.eq(false);
         });
@@ -136,7 +154,11 @@ describe('OrderStateUtils', () => {
                 1,
             );
 
-            const orderStateUtils = new OrderStateUtils(mockBalanceFetcher, mockOrderFilledFetcher);
+            const orderStateUtils = new OrderStateUtils(
+                mockBalanceFetcher,
+                mockOrderFilledFetcher,
+                CHAIN_ID,
+            );
             const transactionHash = '0xdeadbeef';
             const orderState = await orderStateUtils.getOpenOrderStateAsync(signedOrder, transactionHash);
             expect(orderState.transactionHash).to.eq(transactionHash);
diff --git a/packages/order-utils/test/remaining_fillable_calculator_test.ts b/packages/order-utils/test/remaining_fillable_calculator_test.ts
index affad8f1cb..16143dc60b 100644
--- a/packages/order-utils/test/remaining_fillable_calculator_test.ts
+++ b/packages/order-utils/test/remaining_fillable_calculator_test.ts
@@ -43,6 +43,7 @@ describe('RemainingFillableCalculator', () => {
         return {
             signature,
             exchangeAddress: zeroAddress,
+            chainId: 1337,
             feeRecipientAddress: zeroAddress,
             senderAddress: zeroAddress,
             makerAddress: zeroAddress,
diff --git a/packages/order-utils/test/signature_utils_test.ts b/packages/order-utils/test/signature_utils_test.ts
index 1c6db80232..8f5932aee9 100644
--- a/packages/order-utils/test/signature_utils_test.ts
+++ b/packages/order-utils/test/signature_utils_test.ts
@@ -20,6 +20,7 @@ const expect = chai.expect;
 describe('Signature utils', () => {
     let makerAddress: string;
     const fakeExchangeContractAddress = '0x1dc4c1cefef38a777b15aa20260a54e584b16c48';
+    const CHAIN_ID = 1337;
     let order: Order;
     let transaction: ZeroExTransaction;
     before(async () => {
@@ -33,6 +34,7 @@ describe('Signature utils', () => {
             makerAssetData: constants.NULL_ADDRESS,
             takerAssetData: constants.NULL_ADDRESS,
             exchangeAddress: fakeExchangeContractAddress,
+            chainId: CHAIN_ID,
             salt: new BigNumber(0),
             makerFee: new BigNumber(0),
             takerFee: new BigNumber(0),
@@ -160,7 +162,7 @@ describe('Signature utils', () => {
     describe('#ecSignOrderAsync', () => {
         it('should default to eth_sign if eth_signTypedData is unavailable', async () => {
             const expectedSignature =
-                '0x1c3582f06356a1314dbf1c0e534c4d8e92e59b056ee607a7ff5a825f5f2cc5e6151c5cc7fdd420f5608e4d5bef108e42ad90c7a4b408caef32e24374cf387b0d7603';
+                '0x1bcbeb571648db1b7e0454175a6a4b4da1ac07cfc5fb5e4c8e4e10aa4aad368a11050ac85be1ca543eb4e1c07b852cbe6619cbab0cbbf05df364d80e126ffe731403';
 
             const fakeProvider = {
                 async sendAsync(payload: JSONRPCRequestPayload, callback: JSONRPCErrorCallback): Promise<void> {
@@ -356,7 +358,7 @@ describe('Signature utils', () => {
         });
         it('should return the correct Signature for signatureHex concatenated as R + S + V', async () => {
             const expectedSignature =
-                '0x1cd472c439833774b55d248c31b6585f21aea1b9363ebb4ec58549e46b62eb5a6f696f5781f62de008ee7f77650ef940d99c97ec1dee67b3f5cea1bbfdfeb2eba602';
+                '0x1baf6c2d23afb5389e29e4274e3dc419939641e94f56a62260a004f2f79b9501c725a1d740c75d1f6e0bdc7b158c62e1ec36b7e9a16086f249fd821fa00d5652db02';
             const fakeProvider = {
                 async sendAsync(payload: JSONRPCRequestPayload, callback: JSONRPCErrorCallback): Promise<void> {
                     if (payload.method === 'eth_signTypedData') {
diff --git a/packages/order-utils/test/transaction_hash_test.ts b/packages/order-utils/test/transaction_hash_test.ts
index c7ca33a643..c2fcd6225c 100644
--- a/packages/order-utils/test/transaction_hash_test.ts
+++ b/packages/order-utils/test/transaction_hash_test.ts
@@ -14,10 +14,11 @@ const expect = chai.expect;
 
 describe('0x transaction hashing', () => {
     describe('#getTransactionHashHex', () => {
-        const expectedTransactionHash = '0x82c9bb2dcac4f868ec7a15c20ff6175cfc384c20ae6a872aa0342a840f108c2b';
+        const expectedTransactionHash = '0xbd640f97452817179076e736257ea85feac51530f1844ef05297af69e375522b';
         const fakeVerifyingContractAddress = '0x5e72914535f202659083db3a02c984188fa26e9f';
         const transaction: ZeroExTransaction = {
             verifyingContractAddress: fakeVerifyingContractAddress,
+            chainId: 1337,
             signerAddress: constants.NULL_ADDRESS,
             salt: new BigNumber(0),
             data: constants.NULL_BYTES,
diff --git a/packages/order-utils/test/utils/test_order_factory.ts b/packages/order-utils/test/utils/test_order_factory.ts
index 4efe0b38ee..4f5c6b453f 100644
--- a/packages/order-utils/test/utils/test_order_factory.ts
+++ b/packages/order-utils/test/utils/test_order_factory.ts
@@ -11,6 +11,7 @@ const BASE_TEST_ORDER: Order = orderFactory.createOrder(
     constants.ZERO_AMOUNT,
     constants.NULL_ERC20_ASSET_DATA,
     constants.NULL_ADDRESS,
+    0,
 );
 const BASE_TEST_SIGNED_ORDER: SignedOrder = {
     ...BASE_TEST_ORDER,
diff --git a/packages/types/src/index.ts b/packages/types/src/index.ts
index 96e061ade8..44e59c5fff 100644
--- a/packages/types/src/index.ts
+++ b/packages/types/src/index.ts
@@ -18,6 +18,7 @@ export interface Order {
     takerAssetData: string;
     salt: BigNumber;
     exchangeAddress: string;
+    chainId: number;
     feeRecipientAddress: string;
     expirationTimeSeconds: BigNumber;
 }
@@ -51,6 +52,7 @@ export enum MarketOperation {
  */
 export interface ZeroExTransaction {
     verifyingContractAddress: string;
+    chainId: number;
     salt: BigNumber;
     signerAddress: string;
     data: string;
diff --git a/packages/utils/src/provider_utils.ts b/packages/utils/src/provider_utils.ts
index 7ed74b8899..ce20d16a07 100644
--- a/packages/utils/src/provider_utils.ts
+++ b/packages/utils/src/provider_utils.ts
@@ -2,6 +2,7 @@ import {
     EIP1193Provider,
     JSONRPCErrorCallback,
     JSONRPCRequestPayload,
+    JSONRPCResponsePayload,
     SupportedProvider,
     ZeroExProvider,
 } from 'ethereum-types';
@@ -94,4 +95,30 @@ export const providerUtils = {
             `Unsupported provider found. Please make sure it conforms to one of the supported providers. See 'Provider' type in 'ethereum-types' package.`,
         );
     },
+
+    /**
+     * Retrieve the chain ID from a supported provider.
+     * @param supportedProvider A supported provider instance.
+     * @return A promise thar resolves to the chain ID of the network the provider
+     * is connected to.
+     */
+     async getChainIdAsync(supportedProvider: SupportedProvider): Promise<number> {
+         const provider = this.standardizeOrThrow(supportedProvider);
+         return new Promise<number>((accept, reject) => {
+             provider.sendAsync({
+                     jsonrpc: '2.0',
+                     id: _.random(0, 2**64),
+                     method: 'net_version',
+                     params: []
+                 },
+                 (err : Error | null, result?: JSONRPCResponsePayload) => {
+                     if (!_.isNil(err))
+                        reject(err);
+                     if (!result)
+                        throw new Error('Invalid \'net_version\' response');
+                     accept(_.toNumber(result.result));
+                 }
+            );
+        });
+     },
 };
diff --git a/packages/utils/src/sign_typed_data_utils.ts b/packages/utils/src/sign_typed_data_utils.ts
index adb66622d0..87df3d816e 100644
--- a/packages/utils/src/sign_typed_data_utils.ts
+++ b/packages/utils/src/sign_typed_data_utils.ts
@@ -71,8 +71,13 @@ export const signTypedDataUtils = {
         return ethers.utils.defaultAbiCoder.encode(encodedTypes, encodedValues);
     },
     _normalizeValue(type: string, value: any): EIP712ObjectValue {
-        const normalizedValue = type === 'uint256' && BigNumber.isBigNumber(value) ? value.toString() : value;
-        return normalizedValue;
+        if (type == 'uint256') {
+            if (BigNumber.isBigNumber(value)) {
+                return value.toString(10);
+            }
+            return new BigNumber(value).toString(10);
+        }
+        return value;
     },
     _typeHash(primaryType: string, types: EIP712Types): Buffer {
         return ethUtil.sha3(signTypedDataUtils._encodeType(primaryType, types));
diff --git a/packages/utils/test/sign_typed_data_utils_test.ts b/packages/utils/test/sign_typed_data_utils_test.ts
index 3d2cb2496c..0bccab1f96 100644
--- a/packages/utils/test/sign_typed_data_utils_test.ts
+++ b/packages/utils/test/sign_typed_data_utils_test.ts
@@ -36,7 +36,7 @@ describe('signTypedDataUtils', () => {
             },
             primaryType: 'Test',
         };
-        const orderSignTypedDataHashHex = '0x55eaa6ec02f3224d30873577e9ddd069a288c16d6fb407210eecbc501fa76692';
+        const orderSignTypedDataHashHex = '0x78772b297e1b0b31089589a6608930cceba855af9d3ccf7b92cf47fa881e21f7';
         const orderSignTypedData = {
             types: {
                 EIP712Domain: [
@@ -48,6 +48,10 @@ describe('signTypedDataUtils', () => {
                         name: 'version',
                         type: 'string',
                     },
+                    {
+                        name: 'chainId',
+                        type: 'uint256',
+                    },
                     {
                         name: 'verifyingContract',
                         type: 'address',
@@ -107,6 +111,7 @@ describe('signTypedDataUtils', () => {
             domain: {
                 name: '0x Protocol',
                 version: '2',
+                chainId: 1337,
                 verifyingContract: '0x0000000000000000000000000000000000000000',
             },
             message: {
@@ -157,7 +162,7 @@ describe('signTypedDataUtils', () => {
             };
             const hash = signTypedDataUtils.generateTypedDataHash(uninitializedOrder).toString('hex');
             const hashHex = `0x${hash}`;
-            expect(hashHex).to.be.eq('0xfaa49b35faeb9197e9c3ba7a52075e6dad19739549f153b77dfcf59408a4b422');
+            expect(hashHex).to.be.eq('0x510449a190415c4770080d857a1c654b653a0c054c94a7a8e9f08f623f9e824f');
         });
     });
 });