diff --git a/eth/rollup.go b/eth/rollup.go
index 06df509..fcd4b1c 100644
--- a/eth/rollup.go
+++ b/eth/rollup.go
@@ -333,25 +333,25 @@ type RollupInterface interface {
 
 // RollupClient is the implementation of the interface to the Rollup Smart Contract in ethereum.
 type RollupClient struct {
-	client       *EthereumClient
-	address      ethCommon.Address
-	tokenAddress ethCommon.Address
-	gasLimit     uint64
-	contractAbi  abi.ABI
+	client          *EthereumClient
+	address         ethCommon.Address
+	tokenHEZAddress ethCommon.Address
+	gasLimit        uint64
+	contractAbi     abi.ABI
 }
 
 // NewRollupClient creates a new RollupClient
-func NewRollupClient(client *EthereumClient, address ethCommon.Address, tokenAddress ethCommon.Address) (*RollupClient, error) {
+func NewRollupClient(client *EthereumClient, address ethCommon.Address, tokenHEZAddress ethCommon.Address) (*RollupClient, error) {
 	contractAbi, err := abi.JSON(strings.NewReader(string(Hermez.HermezABI)))
 	if err != nil {
 		return nil, err
 	}
 	return &RollupClient{
-		client:       client,
-		address:      address,
-		tokenAddress: tokenAddress,
-		gasLimit:     1000000, //nolint:gomnd
-		contractAbi:  contractAbi,
+		client:          client,
+		address:         address,
+		tokenHEZAddress: tokenHEZAddress,
+		gasLimit:        1000000, //nolint:gomnd
+		contractAbi:     contractAbi,
 	}, nil
 }
 
@@ -371,7 +371,7 @@ func (c *RollupClient) RollupForgeBatch(args *RollupForgeBatchArgs) (*types.Tran
 				return nil, err
 			}
 			nLevels := rollupConst.Verifiers[args.VerifierIdx].NLevels
-			lenBytes := nLevels / 8
+			lenBytes := nLevels / 8 //nolint:gomnd
 			newLastIdx := big.NewInt(int64(args.NewLastIdx))
 			var l1CoordinatorBytes []byte
 			for i := 0; i < len(args.L1CoordinatorTxs); i++ {
@@ -408,14 +408,16 @@ func (c *RollupClient) RollupForgeBatch(args *RollupForgeBatchArgs) (*types.Tran
 	return tx, nil
 }
 
-// RollupAddToken is the interface to call the smart contract function
+// RollupAddToken is the interface to call the smart contract function.
+// `feeAddToken` is the amount of HEZ tokens that will be paid to add the
+// token.  `feeAddToken` must match the public value of the smart contract.
 func (c *RollupClient) RollupAddToken(tokenAddress ethCommon.Address, feeAddToken *big.Int) (*types.Transaction, error) {
 	var tx *types.Transaction
 	var err error
 	if tx, err = c.client.CallAuth(
 		c.gasLimit,
 		func(ec *ethclient.Client, auth *bind.TransactOpts) (*types.Transaction, error) {
-			tokens, err := ERC777.NewERC777(c.tokenAddress, ec)
+			tokens, err := ERC777.NewERC777(c.tokenHEZAddress, ec)
 			if err != nil {
 				return nil, err
 			}
diff --git a/eth/rollup_test.go b/eth/rollup_test.go
index 6920e50..f7725fe 100644
--- a/eth/rollup_test.go
+++ b/eth/rollup_test.go
@@ -35,8 +35,7 @@ func TestRollupConstants(t *testing.T) {
 }
 
 func TestAddToken(t *testing.T) {
-	var feeAddToken = new(big.Int)
-	feeAddToken = big.NewInt(10)
+	feeAddToken := big.NewInt(10)
 	// Addtoken
 	_, err := rollupClient.RollupAddToken(tokenERC777AddressConst, feeAddToken)
 	require.Nil(t, err)
diff --git a/synchronizer/synchronizer_test.go b/synchronizer/synchronizer_test.go
index db6b8eb..ad277f8 100644
--- a/synchronizer/synchronizer_test.go
+++ b/synchronizer/synchronizer_test.go
@@ -74,7 +74,8 @@ D (3): 15
 	// require.Greater(t, len(tokens), 0)
 
 	for i := 1; i <= 3; i++ {
-		_, err := client.RollupAddToken(ethCommon.BigToAddress(big.NewInt(int64(i * 10000))))
+		_, err := client.RollupAddToken(ethCommon.BigToAddress(big.NewInt(int64(i*10000))),
+			clientSetup.RollupVariables.FeeAddToken)
 		require.Nil(t, err)
 	}
 
diff --git a/test/ethclient.go b/test/ethclient.go
index 3c32d0f..47181ef 100644
--- a/test/ethclient.go
+++ b/test/ethclient.go
@@ -690,7 +690,7 @@ func (c *Client) addBatch(args *eth.RollupForgeBatchArgs) (*types.Transaction, e
 }
 
 // RollupAddToken is the interface to call the smart contract function
-func (c *Client) RollupAddToken(tokenAddress ethCommon.Address) (tx *types.Transaction, err error) {
+func (c *Client) RollupAddToken(tokenAddress ethCommon.Address, feeAddToken *big.Int) (tx *types.Transaction, err error) {
 	c.rw.Lock()
 	defer c.rw.Unlock()
 	cpy := c.nextBlock().copy()
@@ -704,6 +704,9 @@ func (c *Client) RollupAddToken(tokenAddress ethCommon.Address) (tx *types.Trans
 	if _, ok := r.State.TokenMap[tokenAddress]; ok {
 		return nil, fmt.Errorf("Token %v already registered", tokenAddress)
 	}
+	if feeAddToken.Cmp(r.Vars.FeeAddToken) != 0 {
+		return nil, fmt.Errorf("Expected fee: %v but got: %v", r.Vars.FeeAddToken, feeAddToken)
+	}
 
 	r.State.TokenMap[tokenAddress] = true
 	r.State.TokenList = append(r.State.TokenList, tokenAddress)
diff --git a/test/ethclient_test.go b/test/ethclient_test.go
index 66b9a78..a55c5d9 100644
--- a/test/ethclient_test.go
+++ b/test/ethclient_test.go
@@ -143,7 +143,7 @@ func TestClientRollup(t *testing.T) {
 
 	// Add a token
 
-	tx, err := c.RollupAddToken(token1Addr)
+	tx, err := c.RollupAddToken(token1Addr, clientSetup.RollupVariables.FeeAddToken)
 	require.Nil(t, err)
 	assert.NotNil(t, tx)