diff --git a/test/ecdsa.js b/test/ecdsa.js
index f6e1410..cbae3d6 100644
--- a/test/ecdsa.js
+++ b/test/ecdsa.js
@@ -50,14 +50,14 @@ describe('ecdsa', function () {
         .onCall(2).returns(new BigInteger('42')) // valid, but 'bad' signature
         .onCall(3).returns(new BigInteger('53')) // valid, good signature
 
-      var checkSig = this.mock()
-      checkSig.exactly(2)
-      checkSig.onCall(0).returns(false) // bad signature
-      checkSig.onCall(1).returns(true) // good signature
+      var mockCheckSig = this.mock()
+      mockCheckSig.exactly(2)
+      mockCheckSig.onCall(0).returns(false) // bad signature
+      mockCheckSig.onCall(1).returns(true) // good signature
 
       var x = new BigInteger('1').toBuffer(32)
       var h1 = new Buffer(32)
-      var k = ecdsa.deterministicGenerateK(h1, x, checkSig)
+      var k = ecdsa.deterministicGenerateK(h1, x, mockCheckSig)
 
       assert.strictEqual(k.toString(), '53')
     }))
diff --git a/test/hdnode.js b/test/hdnode.js
index b48b9e5..d12fa42 100644
--- a/test/hdnode.js
+++ b/test/hdnode.js
@@ -298,7 +298,7 @@ describe('HDNode', function () {
       })
 
       // FIXME: test data is only testing Private -> private for now
-      f.children.forEach(function (c, i) {
+      f.children.forEach(function (c) {
         if (c.m === undefined) return
 
         it(c.path + ' from ' + f.master.fingerprint, function () {
diff --git a/test/integration/_blockchain.js b/test/integration/_blockchain.js
index 3a93a44..e3fdbb1 100644
--- a/test/integration/_blockchain.js
+++ b/test/integration/_blockchain.js
@@ -25,7 +25,7 @@ function fundAddress (unspents, outputs, callback) {
     txb.addOutput(x.address || kpAddress, x.value)
   })
 
-  result.inputs.forEach(function (x, i) {
+  result.inputs.forEach(function (_, i) {
     txb.sign(i, keyPair)
   })
 
@@ -37,7 +37,7 @@ function fundAddress (unspents, outputs, callback) {
 
     // FIXME: @blocktrail can be very slow, give it time
     setTimeout(() => {
-      callback(null, outputs.map(function (x, i) {
+      callback(null, outputs.map(function (_, i) {
         return { txId: txId, vout: i }
       }))
     }, 3000)
diff --git a/test/integration/multisig.js b/test/integration/multisig.js
index 1d4c06f..4b8eb2e 100644
--- a/test/integration/multisig.js
+++ b/test/integration/multisig.js
@@ -62,8 +62,8 @@ describe('bitcoinjs-lib (multisig)', function () {
             // check that the above transaction included the intended address
             blockchain.t.addresses.unspents(blockchain.t.RETURN, function (err, unspents) {
               if (err) return callback(err)
-              if (!unspents.some(function (unspent) {
-                return unspent.txId === txId && unspent.value === 1e4
+              if (!unspents.some(function (x) {
+                return x.txId === txId && x.value === 1e4
               })) return callback(new Error('Could not find unspent after broadcast'))
 
               callback()
diff --git a/test/transaction_builder.js b/test/transaction_builder.js
index 130a319..09400cd 100644
--- a/test/transaction_builder.js
+++ b/test/transaction_builder.js
@@ -101,9 +101,9 @@ describe('TransactionBuilder', function () {
         var tx = new Transaction()
 
         f.inputs.forEach(function (input) {
-          var txHash = new Buffer(input.txId, 'hex').reverse()
+          var txHash2 = new Buffer(input.txId, 'hex').reverse()
 
-          tx.addInput(txHash, input.vout, undefined, bscript.fromASM(input.scriptSig))
+          tx.addInput(txHash2, input.vout, undefined, bscript.fromASM(input.scriptSig))
         })
 
         f.outputs.forEach(function (output) {
@@ -281,7 +281,7 @@ describe('TransactionBuilder', function () {
         f.inputs.forEach(function (input, index) {
           input.signs.forEach(function (sign) {
             var keyPairNetwork = NETWORKS[sign.network || f.network]
-            var keyPair = ECPair.fromWIF(sign.keyPair, keyPairNetwork)
+            var keyPair2 = ECPair.fromWIF(sign.keyPair, keyPairNetwork)
             var redeemScript
 
             if (sign.redeemScript) {
@@ -289,10 +289,10 @@ describe('TransactionBuilder', function () {
             }
 
             if (!sign.throws) {
-              txb.sign(index, keyPair, redeemScript, sign.hashType, sign.value)
+              txb.sign(index, keyPair2, redeemScript, sign.hashType, sign.value)
             } else {
               assert.throws(function () {
-                txb.sign(index, keyPair, redeemScript, sign.hashType, sign.value)
+                txb.sign(index, keyPair2, redeemScript, sign.hashType, sign.value)
               }, new RegExp(f.exception))
             }
           })
@@ -386,8 +386,8 @@ describe('TransactionBuilder', function () {
               txb = TransactionBuilder.fromTransaction(tx, network)
             }
 
-            var keyPair = ECPair.fromWIF(sign.keyPair, network)
-            txb.sign(i, keyPair, redeemScript, sign.hashType)
+            var keyPair2 = ECPair.fromWIF(sign.keyPair, network)
+            txb.sign(i, keyPair2, redeemScript, sign.hashType)
 
             // update the tx
             tx = txb.buildIncomplete()
@@ -417,8 +417,8 @@ describe('TransactionBuilder', function () {
       // now import the Transaction
       var txb = TransactionBuilder.fromTransaction(tx, NETWORKS.testnet)
 
-      var keyPair = ECPair.fromWIF('91avARGdfge8E4tZfYLoxeJ5sGBdNJQH4kvjJoQFacbgx3cTMqe', network)
-      txb.sign(0, keyPair, redeemScript)
+      var keyPair2 = ECPair.fromWIF('91avARGdfge8E4tZfYLoxeJ5sGBdNJQH4kvjJoQFacbgx3cTMqe', network)
+      txb.sign(0, keyPair2, redeemScript)
 
       var tx2 = txb.build()
       assert.equal(tx2.getId(), 'eab59618a564e361adef6d918bd792903c3d41bcf1220137364fb847880467f9')