diff --git a/lib/transaction/transaction.js b/lib/transaction/transaction.js
index b494880..5138d7b 100644
--- a/lib/transaction/transaction.js
+++ b/lib/transaction/transaction.js
@@ -912,28 +912,19 @@ Transaction.prototype.removeOutput = function(index) {
  * @return {Transaction} this
  */
 Transaction.prototype.sort = function() {
-  this.sortOutputs(function(outputs) {
-    var copy = Array.prototype.concat.apply([], outputs);
+  this.sortInputs(function(inputs) {
+    var copy = Array.prototype.concat.apply([], inputs);
     copy.sort(function compare(first, second) {
-      if (first.satoshis < second.satoshis) {
-        return -1;
-      } else if (first.satoshis === second.satoshis) {
-        return Buffer.compare(first.script.toBuffer(), second.script.toBuffer());
-      } else {
-        return 1;
-      }
+      return BufferUtil.compare(first.prevTxId, second.prevTxId)
+        || first.outputIndex - second.outputIndex;
     });
     return copy;
   });
-  this.sortInputs(function(inputs) {
-    var copy = Array.prototype.concat.apply([], inputs);
+  this.sortOutputs(function(outputs) {
+    var copy = Array.prototype.concat.apply([], outputs);
     copy.sort(function compare(first, second) {
-      var compareTx = Buffer.compare(first.script.toBuffer(), second.script.toBuffer());
-      if (compareTx === 0) {
-        return first.outputIndex < second.outputIndex ? -1 : 1;
-      } else {
-        return compareTx;
-      }
+      return first.satoshis - second.satoshis
+        || BufferUtil.compare(first.script.toBuffer(), second.script.toBuffer());
     });
     return copy;
   });
diff --git a/lib/util/buffer.js b/lib/util/buffer.js
index c78b939..0cfe5af 100644
--- a/lib/util/buffer.js
+++ b/lib/util/buffer.js
@@ -170,6 +170,49 @@ module.exports = {
   hexToBuffer: function hexToBuffer(string) {
     assert(js.isHexa(string));
     return new buffer.Buffer(string, 'hex');
+  },
+
+  /**
+   * Browser shim for buffer compare
+   *
+   * MIT. Copyright by Feross Aboukhadijeh, and other contributors.
+   * Originally forked from an MIT-licensed module by Romain Beauxis.
+   * @see {https://github.com/feross/buffer/blob/bc33ea4618e6846148e35aee78dfc28d999bdd1c/index.js#L264}
+   */
+  compare: function(a, b) {
+    if (Buffer.compare) {
+      return Buffer.compare(a, b);
+    } else {
+      if (a === b) {
+        return 0;
+      }
+
+      var x = a.length;
+      var y = b.length;
+
+      var i = 0;
+      var len = Math.min(x, y);
+      while (i < len) {
+        if (a[i] !== b[i]) {
+          break;
+        }
+
+        ++i;
+      }
+
+      if (i !== len) {
+        x = a[i];
+        y = b[i];
+      }
+
+      if (x < y) {
+        return -1;
+      }
+      if (y < x) {
+        return 1;
+      }
+      return 0;
+    }
   }
 };
 
diff --git a/package.json b/package.json
index 736a02c..f474151 100644
--- a/package.json
+++ b/package.json
@@ -68,6 +68,7 @@
     "bip21",
     "bip32",
     "bip37",
+    "bip39",
     "bip70",
     "multisig"
   ],
diff --git a/test/data/bip69.json b/test/data/bip69.json
new file mode 100644
index 0000000..7a46d81
--- /dev/null
+++ b/test/data/bip69.json
@@ -0,0 +1,215 @@
+{
+  "inputs": [
+    {
+      "description": "Ordered by txId, descending (reverse-byte-order ascending)",
+      "inputs": [
+        {
+          "txId": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+          "vout": 0
+        },
+        {
+          "txId": "cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
+          "vout": 0
+        },
+        {
+          "txId": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+          "vout": 0
+        },
+        {
+          "txId": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbff",
+          "vout": 0
+        },
+        {
+          "txId": "ffbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+          "vout": 0
+        }
+      ],
+      "expected": [0, 2, 3, 1, 4]
+    },
+    {
+      "description": "Ordered by vout, ascending",
+      "inputs": [
+        {
+          "txId": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+          "vout": 1
+        },
+        {
+          "txId": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+          "vout": 2
+        },
+        {
+          "txId": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+          "vout": 0
+        }
+      ],
+      "expected": [2, 0, 1]
+    },
+    {
+      "description": "Ordered by txId, then vout",
+      "inputs": [
+        {
+          "txId": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+          "vout": 99
+        },
+        {
+          "txId": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+          "vout": 99
+        },
+        {
+          "txId": "cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
+          "vout": 0
+        },
+        {
+          "txId": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+          "vout": 0
+        }
+      ],
+      "expected": [0, 3, 1, 2]
+    },
+    {
+      "description": "BIP69 test vector 1",
+      "inputs": [
+        { "txId": "0e53ec5dfb2cb8a71fec32dc9a634a35b7e24799295ddd5278217822e0b31f57", "vout": 0 },
+        { "txId": "26aa6e6d8b9e49bb0630aac301db6757c02e3619feb4ee0eea81eb1672947024", "vout": 1 },
+        { "txId": "28e0fdd185542f2c6ea19030b0796051e7772b6026dd5ddccd7a2f93b73e6fc2", "vout": 0 },
+        { "txId": "381de9b9ae1a94d9c17f6a08ef9d341a5ce29e2e60c36a52d333ff6203e58d5d", "vout": 1 },
+        { "txId": "3b8b2f8efceb60ba78ca8bba206a137f14cb5ea4035e761ee204302d46b98de2", "vout": 0 },
+        { "txId": "402b2c02411720bf409eff60d05adad684f135838962823f3614cc657dd7bc0a", "vout": 1 },
+        { "txId": "54ffff182965ed0957dba1239c27164ace5a73c9b62a660c74b7b7f15ff61e7a", "vout": 1 },
+        { "txId": "643e5f4e66373a57251fb173151e838ccd27d279aca882997e005016bb53d5aa", "vout": 0 },
+        { "txId": "6c1d56f31b2de4bfc6aaea28396b333102b1f600da9c6d6149e96ca43f1102b1", "vout": 1 },
+        { "txId": "7a1de137cbafb5c70405455c49c5104ca3057a1f1243e6563bb9245c9c88c191", "vout": 0 },
+        { "txId": "7d037ceb2ee0dc03e82f17be7935d238b35d1deabf953a892a4507bfbeeb3ba4", "vout": 1 },
+        { "txId": "a5e899dddb28776ea9ddac0a502316d53a4a3fca607c72f66c470e0412e34086", "vout": 0 },
+        { "txId": "b4112b8f900a7ca0c8b0e7c4dfad35c6be5f6be46b3458974988e1cdb2fa61b8", "vout": 0 },
+        { "txId": "bafd65e3c7f3f9fdfdc1ddb026131b278c3be1af90a4a6ffa78c4658f9ec0c85", "vout": 0 },
+        { "txId": "de0411a1e97484a2804ff1dbde260ac19de841bebad1880c782941aca883b4e9", "vout": 1 },
+        { "txId": "f0a130a84912d03c1d284974f563c5949ac13f8342b8112edff52971599e6a45", "vout": 0 },
+        { "txId": "f320832a9d2e2452af63154bc687493484a0e7745ebd3aaf9ca19eb80834ad60", "vout": 0 }
+      ],
+      "expected": [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]
+    },
+    {
+      "description": "BIP69 test vector 2",
+      "inputs": [
+        { "txId": "35288d269cee1941eaebb2ea85e32b42cdb2b04284a56d8b14dcc3f5c65d6055", "vout": 0 },
+        { "txId": "35288d269cee1941eaebb2ea85e32b42cdb2b04284a56d8b14dcc3f5c65d6055", "vout": 1 }
+      ],
+      "expected": [0, 1]
+    }
+  ],
+  "outputs": [
+    {
+      "description": "Ordered by Amount, ascending",
+      "outputs": [
+        {
+          "script": "00000000",
+          "value": 3000
+        },
+        {
+          "script": "00000000",
+          "value": 2000
+        },
+        {
+          "script": "00000000",
+          "value": 1000
+        }
+      ],
+      "expected": [2, 1, 0]
+    },
+    {
+      "description": "Ordered by Script, ascending",
+      "outputs": [
+        {
+          "script": "00000000",
+          "value": 1000
+        },
+        {
+          "script": "22222222",
+          "value": 1000
+        },
+        {
+          "script": "11111111",
+          "value": 1000
+        }
+      ],
+      "expected": [0, 2, 1]
+    },
+    {
+      "description": "Ordered by Amount, then Script",
+      "outputs": [
+        {
+          "script": "11111111",
+          "value": 1000
+        },
+        {
+          "script": "11111111",
+          "value": 2000
+        },
+        {
+          "script": "00000000",
+          "value": 3000
+        },
+        {
+          "script": "00000000",
+          "value": 2000
+        }
+      ],
+      "expected": [0, 3, 1, 2]
+    },
+    {
+      "description": "Sorting is irrelevant for equivalent outputs",
+      "outputs": [
+        {
+          "script": "00000000",
+          "value": 2000
+        },
+        {
+          "script": "11111111",
+          "value": 2000
+        },
+        {
+          "script": "00000000",
+          "value": 2000
+        },
+        {
+          "script": "11111111",
+          "value": 3000
+        },
+        {
+          "script": "22222222",
+          "value": 3000
+        }
+      ],
+      "expected": [0, 2, 1, 3, 4]
+    },
+    {
+      "description": "BIP69 test vector 1",
+      "outputs": [
+        {
+          "script": "76a9144a5fba237213a062f6f57978f796390bdcf8d01588ac",
+          "value": 400057456
+        },
+        {
+          "script": "76a9145be32612930b8323add2212a4ec03c1562084f8488ac",
+          "value": 40000000000
+        }
+      ],
+      "expected": [0, 1]
+    },
+    {
+      "description": "BIP69 test vector 2",
+      "outputs": [
+        {
+          "script": "41046a0765b5865641ce08dd39690aade26dfbf5511430ca428a3089261361cef170e3929a68aee3d8d4848b0c5111b0a37b82b86ad559fd2a745b44d8e8d9dfdc0cac",
+          "value": 100000000
+        },
+        {
+          "script": "41044a656f065871a353f216ca26cef8dde2f03e8c16202d2e8ad769f02032cb86a5eb5e56842e92e19141d60a01928f8dd2c875a390f67c1f6c94cfc617c0ea45afac",
+          "value": 2400000000
+        }
+      ],
+      "expected": [0, 1]
+    }
+  ]
+}
diff --git a/test/transaction/transaction.js b/test/transaction/transaction.js
index 5f7720a..598d9eb 100644
--- a/test/transaction/transaction.js
+++ b/test/transaction/transaction.js
@@ -10,6 +10,8 @@ var sinon = require('sinon');
 var bitcore = require('../..');
 var BN = bitcore.crypto.BN;
 var Transaction = bitcore.Transaction;
+var Input = bitcore.Transaction.Input;
+var Output = bitcore.Transaction.Output;
 var PrivateKey = bitcore.PrivateKey;
 var Script = bitcore.Script;
 var Address = bitcore.Address;
@@ -977,9 +979,56 @@ describe('Transaction', function() {
       tx.outputs[1].script.toString().should.equal('OP_0');
       tx.outputs[2].script.toString().should.equal('0x01');
     });
+
+    describe('bitcoinjs fixtures', function() {
+
+      var fixture = require('../data/bip69.json');
+
+      // returns index-based order of sorted against original
+      var getIndexOrder = function(original, sorted) {
+        return sorted.map(function (value) {
+          return original.indexOf(value);
+        });
+      };
+
+      fixture.inputs.forEach(function(inputSet) {
+        it(inputSet.description, function() {
+          var tx = new Transaction();
+          inputSet.inputs = inputSet.inputs.map(function(input) {
+            var input = new Input({
+              prevTxId: input.txId,
+              outputIndex: input.vout,
+              script: new Script(),
+              output: new Output({ script: new Script(), satoshis: 0 })
+            });
+            input.clearSignatures = function () {};
+            return input;
+          });
+          tx.inputs = inputSet.inputs;
+          tx.sort();
+          getIndexOrder(inputSet.inputs, tx.inputs).should.deep.equal(inputSet.expected);
+        });
+      });
+      fixture.outputs.forEach(function(outputSet) {
+        it(outputSet.description, function() {
+          var tx = new Transaction();
+          outputSet.outputs = outputSet.outputs.map(function(output) {
+            return new Output({
+              script: new Script(output.script),
+              satoshis: output.value
+            });
+          });
+          tx.outputs = outputSet.outputs;
+          tx.sort();
+          getIndexOrder(outputSet.outputs, tx.outputs).should.deep.equal(outputSet.expected);
+        });
+      });
+
+    });
   });
 });
 
+
 var tx_empty_hex = '01000000000000000000';
 
 /* jshint maxlen: 1000 */