diff --git a/.travis.yml b/.travis.yml
index ec208c6a..1a817bc8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,7 +18,7 @@ before_install:
       -e BIGCHAINDB_KEYPAIR_PRIVATE=5C5Cknco7YxBRP9AgB1cbUVTL4FAcooxErLygw1DeG2D
       -e BIGCHAINDB_DATABASE_BACKEND=mongodb
       -e BIGCHAINDB_DATABASE_HOST=172.17.0.1
-      bigchaindb/bigchaindb:0.10.2
+      bigchaindb/bigchaindb:master
       start
 
 script: yarn test
diff --git a/package.json b/package.json
index 6d533b1e..43ca2c65 100644
--- a/package.json
+++ b/package.json
@@ -42,11 +42,12 @@
     "babel-runtime": "^6.22.0",
     "cross-env": "^5.0.1",
     "eslint": "^3.14.1",
-    "eslint-config-ascribe": "^3.0.1",
+    "eslint-config-ascribe": "^3.0.4",
     "eslint-plugin-import": "^2.2.0",
     "husky": "^0.13.4",
     "release-it": "^2.7.3",
     "rimraf": "^2.5.4",
+    "sinon": "^2.3.4",
     "webpack": "^2.2.1"
   },
   "dependencies": {
diff --git a/src/transaction/makeOutput.js b/src/transaction/makeOutput.js
index d8eb1f32..820f3c3b 100644
--- a/src/transaction/makeOutput.js
+++ b/src/transaction/makeOutput.js
@@ -3,10 +3,13 @@
  * Create an Output from a Condition.
  * Note: Assumes the given Condition was generated from a single public key (e.g. a Ed25519 Condition)
  * @param {object} condition Condition (e.g. a Ed25519 Condition from `makeEd25519Condition()`)
- * @param {number} amount Amount of the output
+ * @param {string} amount Amount of the output
  * @returns {object} An Output usable in a Transaction
  */
-export default function makeOutput(condition, amount = 1) {
+export default function makeOutput(condition, amount = '1') {
+    if (typeof amount !== 'string') {
+        throw new TypeError('`amount` must be of type string')
+    }
     return {
         'amount': amount,
         condition,
diff --git a/src/transaction/makeTransferTransaction.js b/src/transaction/makeTransferTransaction.js
index d28dae8c..6e9207fc 100644
--- a/src/transaction/makeTransferTransaction.js
+++ b/src/transaction/makeTransferTransaction.js
@@ -14,25 +14,27 @@ import makeTransaction from './makeTransaction'
  *                           For `TRANSFER` Transactions, this should usually just be a list of
  *                           Outputs wrapping Ed25519 Conditions generated from the public keys of
  *                           the recipients.
- * @param {...number} fulfilledOutputs Indices of the Outputs in `unspentTransaction` that this
+ * @param {...number} OutputIndices Indices of the Outputs in `unspentTransaction` that this
  *                                     Transaction fulfills.
- *                                     Note that the public keys listed in the fulfilled Outputs
- *                                     must be used (and in the same order) to sign the Transaction
+ *                                     Note that listed public keys listed must be used (and in
+ *                                     the same order) to sign the Transaction
  *                                     (`signTransaction()`).
  * @returns {object} Unsigned transaction -- make sure to call signTransaction() on it before
  *                   sending it off!
  */
+// TODO:
+// - Make `metadata` optional argument
 export default function makeTransferTransaction(
         unspentTransaction,
         metadata,
         outputs,
-        ...fulfilledOutputs
+        ...outputIndices
     ) {
-    const inputs = fulfilledOutputs.map((outputIndex) => {
+    const inputs = outputIndices.map((outputIndex) => {
         const fulfilledOutput = unspentTransaction.outputs[outputIndex]
         const transactionLink = {
             'output': outputIndex,
-            'txid': unspentTransaction.id,
+            'transaction_id': unspentTransaction.id,
         }
 
         return makeInputTemplate(fulfilledOutput.public_keys, transactionLink)
diff --git a/test/transaction/test_transaction.js b/test/transaction/test_transaction.js
new file mode 100644
index 00000000..6ef3f6d2
--- /dev/null
+++ b/test/transaction/test_transaction.js
@@ -0,0 +1,132 @@
+import test from 'ava'
+import sinon from 'sinon'
+
+import { Transaction, Ed25519Keypair } from '../../src'
+import * as makeTransaction from '../../src/transaction/makeTransaction' // eslint-disable-line
+import makeInputTemplate from '../../src/transaction/makeInputTemplate'
+
+
+// TODO: Find out if ava has something like conftest, if so put this there.
+const alice = new Ed25519Keypair()
+const aliceCondition = Transaction.makeEd25519Condition(alice.publicKey)
+const aliceOutput = Transaction.makeOutput(aliceCondition)
+const assetMessage = { assetMessage: 'assetMessage' }
+const metaDataMessage = { metaDataMessage: 'metaDataMessage' }
+const createTx = Transaction.makeCreateTransaction(
+    assetMessage,
+    metaDataMessage,
+    [aliceOutput],
+    alice.publicKey
+)
+const transferTx = Transaction.makeTransferTransaction(
+    createTx,
+    metaDataMessage,
+    [aliceOutput],
+    0
+)
+
+
+test('Create valid output with default amount', t => {
+    const condition = {
+        details: {
+            public_key: 'abc'
+        }
+    }
+    const expected = {
+        amount: '1',
+        condition,
+        public_keys: ['abc']
+    }
+    const res = Transaction.makeOutput(condition)
+    t.deepEqual(res, expected)
+})
+
+
+test('Create valid output with custom amount', t => {
+    const condition = {
+        details: {
+            public_key: 'abc'
+        }
+    }
+    const customAmount = '1337'
+    const expected = {
+        amount: customAmount,
+        condition,
+        public_keys: ['abc']
+    }
+    const res = Transaction.makeOutput(condition, customAmount)
+    t.deepEqual(res, expected)
+})
+
+test('Pass condition not based on public_keys to makeOutput', t => {
+    const condition = {
+        details: {
+            idea: 'just pretend this is e.g. a hashlock'
+        }
+    }
+    const expected = {
+        amount: '1',
+        condition,
+        public_keys: []
+    }
+    const res = Transaction.makeOutput(condition)
+    t.deepEqual(res, expected)
+})
+
+
+test('makeOutput throws TypeError with incorrect amount type', t => {
+    t.throws(() => Transaction.makeOutput({}, 1337), TypeError)
+})
+
+
+test('Create TRANSFER transaction based on CREATE transaction', t => {
+    sinon.spy(makeTransaction, 'default')
+
+    Transaction.makeTransferTransaction(
+        createTx,
+        metaDataMessage,
+        [aliceOutput],
+        0
+    )
+    const expected = [
+        'TRANSFER',
+        { id: createTx.id },
+        metaDataMessage,
+        [aliceOutput],
+        [makeInputTemplate(
+            [alice.publicKey],
+            { output: 0, transaction_id: createTx.id }
+        )]
+    ]
+
+    // NOTE: `src/transaction/makeTransaction` is `export default`, hence we
+    // can only mock `makeTransaction.default` with a hack:
+    // See: https://stackoverflow.com/a/33676328/1263876
+    t.truthy(makeTransaction.default.calledWith(...expected))
+    makeTransaction.default.restore()
+})
+
+
+test('Create TRANSFER transaction based on TRANSFER transaction', t => {
+    sinon.spy(makeTransaction, 'default')
+
+    Transaction.makeTransferTransaction(
+        transferTx,
+        metaDataMessage,
+        [aliceOutput],
+        0
+    )
+    const expected = [
+        'TRANSFER',
+        { id: transferTx.asset.id },
+        metaDataMessage,
+        [aliceOutput],
+        [makeInputTemplate(
+            [alice.publicKey],
+            { output: 0, transaction_id: transferTx.id }
+        )]
+    ]
+
+    t.truthy(makeTransaction.default.calledWith(...expected))
+    makeTransaction.default.restore()
+})