diff --git a/src/connection/index.js b/src/connection/index.js
index 48d9a67..aa7131e 100644
--- a/src/connection/index.js
+++ b/src/connection/index.js
@@ -89,7 +89,7 @@ export default class Connection {
         // NOTE: If `spent` is not defined, it must not be included in the
         // query parameters.
         if (spent !== undefined) {
-            query.spent = spent
+            query.spent = spent.toString()
         }
         return this._req(this.getApiUrls('outputs'), {
             query
diff --git a/test/connection/test_connection.js b/test/connection/test_connection.js
index af398c5..eb7bf34 100644
--- a/test/connection/test_connection.js
+++ b/test/connection/test_connection.js
@@ -157,7 +157,7 @@ test('Get outputs for a public key and spent=false', t => {
     conn.listOutputs(publicKey, spent)
     t.truthy(conn._req.calledWith(
         expectedPath,
-        { query: { public_key: publicKey, spent } }
+        { query: { public_key: publicKey, spent: 'false' } }
     ))
 })
 
@@ -173,7 +173,7 @@ test('Get outputs for a public key and spent=true', t => {
     conn.listOutputs(publicKey, spent)
     t.truthy(conn._req.calledWith(
         expectedPath,
-        { query: { public_key: publicKey, spent } }
+        { query: { public_key: publicKey, spent: 'true' } }
     ))
 })
 
diff --git a/test/integration/test_integration.js b/test/integration/test_integration.js
index 5b1d184..b6808d5 100644
--- a/test/integration/test_integration.js
+++ b/test/integration/test_integration.js
@@ -112,137 +112,130 @@ test('Valid TRANSFER transaction with multiple Ed25519 inputs', t => {
 
 test('Search for spent and unspent outputs of a given public key', t => {
     const conn = new Connection(API_PATH)
+    const carol = new Ed25519Keypair()
+    const carolCondition = Transaction.makeEd25519Condition(carol.publicKey)
+    const carolOutput = Transaction.makeOutput(carolCondition)
+    const trent = new Ed25519Keypair()
+    const trentCondition = Transaction.makeEd25519Condition(trent.publicKey)
+    const trentOutput = Transaction.makeOutput(trentCondition)
+
 
     const createTx = Transaction.makeCreateTransaction(
         asset(),
         metaData,
-        [aliceOutput, aliceOutput],
-        alice.publicKey
+        [carolOutput, carolOutput],
+        carol.publicKey
     )
     const createTxSigned = Transaction.signTransaction(
         createTx,
-        alice.privateKey,
-        alice.privateKey
+        carol.privateKey,
+        carol.privateKey
     )
 
     // We spent output 1 (of 0, 1)
     const transferTx = Transaction.makeTransferTransaction(
         createTxSigned,
         metaData,
-        [bobOutput],
+        [trentOutput],
         1
     )
     const transferTxSigned = Transaction.signTransaction(
         transferTx,
-        alice.privateKey,
+        carol.privateKey,
     )
 
-    function byTransactionId(transactionId, ...outputIndices) {
-        return value => transactionId === value.transaction_id &&
-            outputIndices.includes(value.output)
-    }
-
     return conn.postTransaction(createTxSigned)
         .then(({ id }) => conn.pollStatusAndFetchTransaction(id))
         .then(() => conn.postTransaction(transferTxSigned))
         .then(({ id }) => conn.pollStatusAndFetchTransaction(id))
-        .then(() => conn.listOutputs(alice.publicKey))
+        .then(() => conn.listOutputs(carol.publicKey))
         // now listOutputs should return us outputs 0 and 1 (unfiltered)
-        .then(outputs => outputs.filter(byTransactionId(
-            createTxSigned.id,
-            0,
-            1
-        )))
         .then(outputs => t.truthy(outputs.length === 2))
 })
 
 
 test('Search for unspent outputs for a given public key', t => {
     const conn = new Connection(API_PATH)
+    const carol = new Ed25519Keypair()
+    const carolCondition = Transaction.makeEd25519Condition(carol.publicKey)
+    const carolOutput = Transaction.makeOutput(carolCondition)
+    const trent = new Ed25519Keypair()
+    const trentCondition = Transaction.makeEd25519Condition(trent.publicKey)
+    const trentOutput = Transaction.makeOutput(trentCondition)
 
     const createTx = Transaction.makeCreateTransaction(
         asset(),
         metaData,
-        [aliceOutput, aliceOutput, aliceOutput],
-        alice.publicKey
+        [carolOutput, carolOutput, carolOutput],
+        carol.publicKey
     )
     const createTxSigned = Transaction.signTransaction(
         createTx,
-        alice.privateKey,
-        alice.privateKey
+        carol.privateKey,
+        carol.privateKey
     )
 
     // We spent output 1 (of 0, 1, 2)
     const transferTx = Transaction.makeTransferTransaction(
         createTxSigned,
         metaData,
-        [bobOutput],
+        [trentOutput],
         1
     )
     const transferTxSigned = Transaction.signTransaction(
         transferTx,
-        alice.privateKey,
+        carol.privateKey,
     )
 
-    function byTransactionId(transactionId, ...outputIndices) {
-        return value => transactionId === value.transaction_id &&
-            outputIndices.includes(value.output)
-    }
-
     return conn.postTransaction(createTxSigned)
         .then(({ id }) => conn.pollStatusAndFetchTransaction(id))
         .then(() => conn.postTransaction(transferTxSigned))
         .then(({ id }) => conn.pollStatusAndFetchTransaction(id))
         // now listOutputs should return us outputs 0 and 2 (1 is spent)
-        .then(() => conn.listOutputs(alice.publicKey, false))
-        .then(outputs => outputs.filter(byTransactionId(
-            createTxSigned.id,
-            0,
-            2
-        )))
+        .then(() => conn.listOutputs(carol.publicKey, 'false'))
         .then(outputs => t.truthy(outputs.length === 2))
 })
 
 
 test('Search for spent outputs for a given public key', t => {
     const conn = new Connection(API_PATH)
+    const carol = new Ed25519Keypair()
+    const carolCondition = Transaction.makeEd25519Condition(carol.publicKey)
+    const carolOutput = Transaction.makeOutput(carolCondition)
+    const trent = new Ed25519Keypair()
+    const trentCondition = Transaction.makeEd25519Condition(trent.publicKey)
+    const trentOutput = Transaction.makeOutput(trentCondition)
 
     const createTx = Transaction.makeCreateTransaction(
         asset(),
         metaData,
-        [aliceOutput, aliceOutput, aliceOutput],
-        alice.publicKey
+        [carolOutput, carolOutput, carolOutput],
+        carol.publicKey
     )
     const createTxSigned = Transaction.signTransaction(
         createTx,
-        alice.privateKey,
-        alice.privateKey
+        carol.privateKey,
+        carol.privateKey
     )
 
     // We spent output 1 (of 0, 1, 2)
     const transferTx = Transaction.makeTransferTransaction(
         createTxSigned,
         metaData,
-        [bobOutput],
+        [trentOutput],
         1
     )
     const transferTxSigned = Transaction.signTransaction(
         transferTx,
-        alice.privateKey,
+        carol.privateKey,
     )
 
-    function byTransactionId(transactionId, ...outputIndices) {
-        return value => transactionId === value.transaction_id &&
-            outputIndices.includes(value.output)
-    }
-
     return conn.postTransaction(createTxSigned)
         .then(({ id }) => conn.pollStatusAndFetchTransaction(id))
         .then(() => conn.postTransaction(transferTxSigned))
         .then(({ id }) => conn.pollStatusAndFetchTransaction(id))
         // now listOutputs should only return us output 1 (0 and 2 are unspent)
-        .then(() => conn.listOutputs(alice.publicKey, true))
-        .then(outputs => outputs.filter(byTransactionId(createTxSigned.id, 1)))
+        .then(() => conn.listOutputs(carol.publicKey, true))
         .then(outputs => t.truthy(outputs.length === 1))
 })