diff --git a/README.md b/README.md
index 99de881..1df16ab 100644
--- a/README.md
+++ b/README.md
@@ -39,9 +39,7 @@ You can see example usage in cli.js, it works both in console and in browser.
 
 1. `npm install`
 1. `cp .env.example .env`
-1. `npm run build:circuit` - this may take 10 minutes or more
-1. `npm run build:contract`
-1. `npm run browserify`
+1. `npm run build` - this may take 10 minutes or more
 1. `npx ganache-cli`
 1. `npm run test` - optionally run tests. It may fail for the first time, just run one more time.
 
diff --git a/contracts/ERC20Mixer.sol b/contracts/ERC20Mixer.sol
index 9ba94db..5941f0e 100644
--- a/contracts/ERC20Mixer.sol
+++ b/contracts/ERC20Mixer.sol
@@ -18,11 +18,11 @@ contract ERC20Mixer is Mixer {
 
   constructor(
     address _verifier,
+    uint256 _denomination,
     uint8 _merkleTreeHeight,
     uint256 _emptyElement,
     address payable _operator,
-    address _token,
-    uint256 _denomination
+    address _token
   ) Mixer(_verifier, _denomination, _merkleTreeHeight, _emptyElement, _operator) public {
     token = _token;
   }
diff --git a/migrations/5_deploy_erc20_mixer.js b/migrations/5_deploy_erc20_mixer.js
index d71b920..d16e5f4 100644
--- a/migrations/5_deploy_erc20_mixer.js
+++ b/migrations/5_deploy_erc20_mixer.js
@@ -20,11 +20,11 @@ module.exports = function(deployer, network, accounts) {
     const mixer = await deployer.deploy(
       ERC20Mixer,
       verifier.address,
+      TOKEN_AMOUNT,
       MERKLE_TREE_HEIGHT,
       EMPTY_ELEMENT,
       accounts[0],
       token,
-      TOKEN_AMOUNT
     )
     console.log('ERC20Mixer\'s address ', mixer.address)
   })
diff --git a/test/ERC20Mixer.test.js b/test/ERC20Mixer.test.js
index c6b9048..e244017 100644
--- a/test/ERC20Mixer.test.js
+++ b/test/ERC20Mixer.test.js
@@ -52,11 +52,11 @@ contract('ERC20Mixer', accounts => {
   const levels = MERKLE_TREE_HEIGHT || 16
   const zeroValue = EMPTY_ELEMENT || 1337
   let tokenDenomination = TOKEN_AMOUNT || '1000000000000000000' // 1 ether
-  const value = ETH_AMOUNT || '1000000000000000000' // 1 ether
   let snapshotId
   let prefix = 'test'
   let tree
   const fee = bigInt(ETH_AMOUNT).shr(1) || bigInt(1e17)
+  const refund = ETH_AMOUNT || '1000000000000000000' // 1 ether
   const receiver = getRandomReceiver()
   const relayer = accounts[1]
   let groth16
@@ -96,7 +96,7 @@ contract('ERC20Mixer', accounts => {
       const commitment = 43
       await token.approve(mixer.address, tokenDenomination)
 
-      let { logs } = await mixer.deposit(commitment, { value, from: sender })
+      let { logs } = await mixer.deposit(commitment, { from: sender })
 
       logs[0].event.should.be.equal('Deposit')
       logs[0].args.commitment.should.be.eq.BN(toBN(commitment))
@@ -114,9 +114,9 @@ contract('ERC20Mixer', accounts => {
       const balanceUserBefore = await token.balanceOf(user)
       await token.approve(mixer.address, tokenDenomination, { from: user })
       // Uncomment to measure gas usage
-      // let gas = await mixer.deposit.estimateGas(toBN(deposit.commitment.toString()), { value, from: user, gasPrice: '0' })
+      // let gas = await mixer.deposit.estimateGas(toBN(deposit.commitment.toString()), { from: user, gasPrice: '0' })
       // console.log('deposit gas:', gas)
-      await mixer.deposit(toBN(deposit.commitment.toString()), { value, from: user, gasPrice: '0' })
+      await mixer.deposit(toBN(deposit.commitment.toString()), { from: user, gasPrice: '0' })
 
       const balanceUserAfter = await token.balanceOf(user)
       balanceUserAfter.should.be.eq.BN(toBN(balanceUserBefore).sub(toBN(tokenDenomination)))
@@ -130,6 +130,7 @@ contract('ERC20Mixer', accounts => {
         relayer,
         receiver,
         fee,
+        refund,
 
         // private
         nullifier: deposit.nullifier,
@@ -152,7 +153,7 @@ contract('ERC20Mixer', accounts => {
       // Uncomment to measure gas usage
       // gas = await mixer.withdraw.estimateGas(proof, publicSignals, { from: relayer, gasPrice: '0' })
       // console.log('withdraw gas:', gas)
-      const { logs } = await mixer.withdraw(proof, publicSignals, { from: relayer, gasPrice: '0' })
+      const { logs } = await mixer.withdraw(proof, publicSignals, { value: refund, from: relayer, gasPrice: '0' })
 
       const balanceMixerAfter = await token.balanceOf(mixer.address)
       const balanceRelayerAfter = await token.balanceOf(relayer)
@@ -164,7 +165,7 @@ contract('ERC20Mixer', accounts => {
       balanceRelayerAfter.should.be.eq.BN(toBN(balanceRelayerBefore).add(feeBN))
       ethBalanceOperatorAfter.should.be.eq.BN(toBN(ethBalanceOperatorBefore))
       balanceRecieverAfter.should.be.eq.BN(toBN(balanceRecieverBefore).add(toBN(tokenDenomination).sub(feeBN)))
-      ethBalanceRecieverAfter.should.be.eq.BN(toBN(ethBalanceRecieverBefore).add(toBN(value)))
+      ethBalanceRecieverAfter.should.be.eq.BN(toBN(ethBalanceRecieverBefore).add(toBN(refund)))
 
       logs[0].event.should.be.equal('Withdraw')
       logs[0].args.nullifierHash.should.be.eq.BN(toBN(input.nullifierHash.toString()))
@@ -196,7 +197,7 @@ contract('ERC20Mixer', accounts => {
       console.log('approve done')
       const allowanceUser = await usdtToken.allowance(user, mixer.address)
       console.log('allowanceUser', allowanceUser.toString())
-      await mixer.deposit(toBN(deposit.commitment.toString()), { value, from: user, gasPrice: '0' })
+      await mixer.deposit(toBN(deposit.commitment.toString()), { from: user, gasPrice: '0' })
       console.log('deposit done')
 
       const balanceUserAfter = await usdtToken.balanceOf(user)
@@ -212,6 +213,7 @@ contract('ERC20Mixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
 
         // private
         nullifier: deposit.nullifier,
@@ -235,7 +237,7 @@ contract('ERC20Mixer', accounts => {
       // Uncomment to measure gas usage
       // gas = await mixer.withdraw.estimateGas(proof, publicSignals, { from: relayer, gasPrice: '0' })
       // console.log('withdraw gas:', gas)
-      const { logs } = await mixer.withdraw(proof, publicSignals, { from: relayer, gasPrice: '0' })
+      const { logs } = await mixer.withdraw(proof, publicSignals, { value: refund, from: relayer, gasPrice: '0' })
 
       const balanceMixerAfter = await usdtToken.balanceOf(mixer.address)
       const balanceRelayerAfter = await usdtToken.balanceOf(relayer)
@@ -247,7 +249,7 @@ contract('ERC20Mixer', accounts => {
       balanceRelayerAfter.should.be.eq.BN(toBN(balanceRelayerBefore))
       ethBalanceOperatorAfter.should.be.eq.BN(toBN(ethBalanceOperatorBefore).add(feeBN))
       balanceRecieverAfter.should.be.eq.BN(toBN(balanceRecieverBefore).add(toBN(tokenDenomination)))
-      ethBalanceRecieverAfter.should.be.eq.BN(toBN(ethBalanceRecieverBefore).add(toBN(value)).sub(feeBN))
+      ethBalanceRecieverAfter.should.be.eq.BN(toBN(ethBalanceRecieverBefore).add(toBN(refund)).sub(feeBN))
 
 
       logs[0].event.should.be.equal('Withdraw')
@@ -276,7 +278,7 @@ contract('ERC20Mixer', accounts => {
       console.log('balanceUserBefore', balanceUserBefore.toString())
       await token.approve(mixer.address, tokenDenomination, { from: user })
       console.log('approve done')
-      await mixer.deposit(toBN(deposit.commitment.toString()), { value, from: user, gasPrice: '0' })
+      await mixer.deposit(toBN(deposit.commitment.toString()), { from: user, gasPrice: '0' })
       console.log('deposit done')
 
       const balanceUserAfter = await token.balanceOf(user)
@@ -292,6 +294,7 @@ contract('ERC20Mixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
 
         // private
         nullifier: deposit.nullifier,
@@ -315,7 +318,7 @@ contract('ERC20Mixer', accounts => {
       // Uncomment to measure gas usage
       // gas = await mixer.withdraw.estimateGas(proof, publicSignals, { from: relayer, gasPrice: '0' })
       // console.log('withdraw gas:', gas)
-      const { logs } = await mixer.withdraw(proof, publicSignals, { from: relayer, gasPrice: '0' })
+      const { logs } = await mixer.withdraw(proof, publicSignals, { value: refund, from: relayer, gasPrice: '0' })
       console.log('withdraw done')
 
       const balanceMixerAfter = await token.balanceOf(mixer.address)
@@ -328,7 +331,7 @@ contract('ERC20Mixer', accounts => {
       balanceRelayerAfter.should.be.eq.BN(toBN(balanceRelayerBefore))
       ethBalanceOperatorAfter.should.be.eq.BN(toBN(ethBalanceOperatorBefore).add(feeBN))
       balanceRecieverAfter.should.be.eq.BN(toBN(balanceRecieverBefore).add(toBN(tokenDenomination)))
-      ethBalanceRecieverAfter.should.be.eq.BN(toBN(ethBalanceRecieverBefore).add(toBN(value)).sub(feeBN))
+      ethBalanceRecieverAfter.should.be.eq.BN(toBN(ethBalanceRecieverBefore).add(toBN(refund)).sub(feeBN))
 
 
       logs[0].event.should.be.equal('Withdraw')
diff --git a/test/ETHMixer.test.js b/test/ETHMixer.test.js
index affc2c9..ef4ff66 100644
--- a/test/ETHMixer.test.js
+++ b/test/ETHMixer.test.js
@@ -68,6 +68,7 @@ contract('ETHMixer', accounts => {
   let prefix = 'test'
   let tree
   const fee = bigInt(ETH_AMOUNT).shr(1) || bigInt(1e17)
+  const refund = bigInt(0)
   const receiver = getRandomReceiver()
   const relayer = accounts[1]
   let groth16
@@ -144,6 +145,7 @@ contract('ETHMixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
         secret: deposit.secret,
         pathElements: path_elements,
         pathIndex: path_index,
@@ -200,6 +202,7 @@ contract('ETHMixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
 
         // private
         nullifier: deposit.nullifier,
@@ -257,6 +260,7 @@ contract('ETHMixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
         secret: deposit.secret,
         pathElements: path_elements,
         pathIndex: path_index,
@@ -282,6 +286,7 @@ contract('ETHMixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
         secret: deposit.secret,
         pathElements: path_elements,
         pathIndex: path_index,
@@ -307,6 +312,7 @@ contract('ETHMixer', accounts => {
         relayer: operator,
         receiver,
         fee: oneEtherFee,
+        refund,
         secret: deposit.secret,
         pathElements: path_elements,
         pathIndex: path_index,
@@ -332,6 +338,7 @@ contract('ETHMixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
         secret: deposit.secret,
         pathElements: path_elements,
         pathIndex: path_index,
@@ -360,6 +367,7 @@ contract('ETHMixer', accounts => {
         relayer: operator,
         receiver,
         fee,
+        refund,
         secret: deposit.secret,
         pathElements: path_elements,
         pathIndex: path_index,