diff --git a/lib/tests/2wp.js b/lib/tests/2wp.js
index 253f7e64..38fc1c46 100644
--- a/lib/tests/2wp.js
+++ b/lib/tests/2wp.js
@@ -121,11 +121,11 @@ const execute = (description, getRskHost) => {
       const sender2PeginValueInSatoshis = minimumPeginValueInSatoshis;
       const peginValueInSatoshis = sender1PeginValueInSatoshis + sender2PeginValueInSatoshis;
 
-      const sender1UtxosInfo = await btcTxHelper.selectSpendableUTXOsFromAddress(senderRecipientInfo1.btcSenderAddressInfo.address, satoshisToBtc(sender1PeginValueInSatoshis));
-      const sender2UtxosInfo = await btcTxHelper.selectSpendableUTXOsFromAddress(senderRecipientInfo2.btcSenderAddressInfo.address, satoshisToBtc(sender2PeginValueInSatoshis));
+      const sender1UtxosInfo = await btcTxHelper.selectSpendableUTXOsFromAddress(senderRecipientInfo1.btcSenderAddressInfo.address, Number(satoshisToBtc(sender1PeginValueInSatoshis)));
+      const sender2UtxosInfo = await btcTxHelper.selectSpendableUTXOsFromAddress(senderRecipientInfo2.btcSenderAddressInfo.address, Number(satoshisToBtc(sender2PeginValueInSatoshis)));
 
-      const sender1ChangeInSatoshis = btcToSatoshis(sender1UtxosInfo.change);
-      const sender2ChangeInSatoshis = btcToSatoshis(sender2UtxosInfo.change);
+      const sender1ChangeInSatoshis = Number(btcToSatoshis(sender1UtxosInfo.change));
+      const sender2ChangeInSatoshis = Number(btcToSatoshis(sender2UtxosInfo.change));
 
       const tx = new bitcoinJsLib.Transaction();
 
@@ -189,25 +189,25 @@ const execute = (description, getRskHost) => {
       const sender2PeginValueInSatoshis = minimumPeginValueInSatoshis;
       const peginValueInSatoshis = sender1PeginValueInSatoshis + sender2PeginValueInSatoshis;
 
-      const sender1UtxosInfo = await getAddressUtxosInfo(btcTxHelper, senderRecipientInfo1.btcSenderAddressInfo.address, satoshisToBtc(sender1PeginValueInSatoshis));
-      const sender2UtxosInfo = await getAddressUtxosInfo(btcTxHelper, senderRecipientInfo2.btcSenderAddressInfo.address, satoshisToBtc(sender2PeginValueInSatoshis));
+      const sender1UtxosInfo = await btcTxHelper.selectSpendableUTXOsFromAddress(senderRecipientInfo1.btcSenderAddressInfo.address, Number(satoshisToBtc(sender1PeginValueInSatoshis)));
+      const sender2UtxosInfo = await btcTxHelper.selectSpendableUTXOsFromAddress(senderRecipientInfo2.btcSenderAddressInfo.address, Number(satoshisToBtc(sender2PeginValueInSatoshis)));
 
-      const sender1ChangeInSatoshis = btcToSatoshis(sender1UtxosInfo.change);
-      const sender2ChangeInSatoshis = btcToSatoshis(sender2UtxosInfo.change);
+      const sender1ChangeInSatoshis = Number(btcToSatoshis(sender1UtxosInfo.change));
+      const sender2ChangeInSatoshis = Number(btcToSatoshis(sender2UtxosInfo.change));
 
       const tx = new bitcoinJsLib.Transaction();
 
       // Adding inputs
-      addInputs(tx, sender1UtxosInfo);
-      addInputs(tx, sender2UtxosInfo);
+      addInputs(tx, sender1UtxosInfo.utxos);
+      addInputs(tx, sender2UtxosInfo.utxos);
 
       // Adding 2 outputs to the federation
-      addOutputToFed(tx, sender1PeginValueInSatoshis);
-      addOutputToFed(tx, sender2PeginValueInSatoshis);
+      addOutput(tx, federationAddress, sender1PeginValueInSatoshis);
+      addOutput(tx, federationAddress, sender2PeginValueInSatoshis);
 
       // Adding change outputs
-      addChangeOutput(tx, senderRecipientInfo1.btcSenderAddressInfo.address, sender1ChangeInSatoshis);
-      addChangeOutput(tx, senderRecipientInfo2.btcSenderAddressInfo.address, sender2ChangeInSatoshis);
+      addOutput(tx, senderRecipientInfo1.btcSenderAddressInfo.address, sender1ChangeInSatoshis - btcFeeInSatoshis);
+      addOutput(tx, senderRecipientInfo2.btcSenderAddressInfo.address, sender2ChangeInSatoshis - btcFeeInSatoshis);
 
       const sendersPrivateKeys = [senderRecipientInfo1.btcSenderAddressInfo.privateKey, senderRecipientInfo2.btcSenderAddressInfo.privateKey];