diff --git a/browser/util.js b/browser/util.js
index 4c468a066..18a5738b6 100644
--- a/browser/util.js
+++ b/browser/util.js
@@ -145,15 +145,16 @@ Bitcoin.Util = {
     if (i < 0xfd) {
       // unsigned char
       return [i];
-    } else if (i <= 1<<16) {
+    } else if (i < 0x10000) {
       // unsigned short (LE)
-      return [0xfd, i >>> 8, i & 255];
-    } else if (i <= 1<<32) {
+      return [0xfd, i & 255 , i >>> 8];
+    } else if (i < 0x100000000) {
       // unsigned int (LE)
-      return [0xfe].concat(Crypto.util.wordsToBytes([i]));
+      return [0xfe].concat(Crypto.util.wordsToBytes([i]).reverse());
     } else {
+      throw 'quadword not implemented'
       // unsigned long long (LE)
-      return [0xff].concat(Crypto.util.wordsToBytes([i >>> 32, i]));
+      //return [0xff].concat(Crypto.util.wordsToBytes([i >>> 32, i]));
     }
   },
 
diff --git a/test/test.util.js b/test/test.util.js
index b352c5b96..48294b355 100644
--- a/test/test.util.js
+++ b/test/test.util.js
@@ -65,4 +65,52 @@ describe('util', function() {
       });
     });
   });
+  describe('#varIntBuf', function() {
+    var data = [
+      [0, '00' ],
+      [1, '01'],
+      [253, 'fdfd00'],
+      [254, 'fdfe00'],
+      [255, 'fdff00'],
+      [0x100, 'fd0001'],
+      [0x1000, 'fd0010'],
+      [0x1001, 'fd0110'],
+      [0x10000, 'fe00000100'],
+      [0x12345, 'fe45230100'],
+      [0x12345678, 'fe78563412'],
+      [0x123456789a, 'ff9a78563412000000'],
+      [0x123456789abcde, 'ffdebc9a7856341200'],
+    ];
+    data.forEach(function(datum) {
+      var integer = datum[0];
+      var result = datum[1];
+      it('should work for ' + integer, function() {
+        buffertools.toHex(coinUtil.varIntBuf(integer)).should.equal(result);
+      });
+    });
+  });
+  describe('#getVarIntSize', function() {
+    var data = [
+      [0, 1 ],
+      [1, 1],
+      [252, 1],
+      [253, 3],
+      [254, 3],
+      [0x100, 3],
+      [0x1000, 3],
+      [0x1001, 3],
+      [0x10000, 5],
+      [0x10001, 5],
+      [0xffffffff, 5],
+      [0x100000000, 9],
+      [0x100000001, 9],
+    ];
+    data.forEach(function(datum) {
+      var integer = datum[0];
+      var result = datum[1];
+      it('should work for ' + integer, function() {
+        coinUtil.getVarIntSize(integer).should.equal(result);
+      });
+    });
+  });
 });
diff --git a/util/util.js b/util/util.js
index 0dd4d963e..c66bca4c3 100644
--- a/util/util.js
+++ b/util/util.js
@@ -321,13 +321,13 @@ var reverseBytes32 = exports.reverseBytes32 = function (data) {
 
 var getVarIntSize = exports.getVarIntSize = function getVarIntSize(i) {
 
-  if (i < 0xFD) {
+  if (i < 253) {
     // unsigned char
     return 1;
-  } else if (i <= 1<<16) {
+  } else if (i < 0x10000) {
     // unsigned short (LE)
     return 3;
-  } else if (i <= 1<<32) {
+  } else if (i < 0x100000000) {
     // unsigned int (LE)
     return 5;
   } else {
@@ -350,7 +350,10 @@ var varIntBuf = exports.varIntBuf = function varIntBuf(n) {
     buf.writeUInt8(254, 0);
     buf.writeUInt32LE(n, 1);
   } else {
-    throw new Error("quadword not supported");
+    buf = new Buffer(1 + 8);
+    buf.writeUInt8(255, 0);
+    buf.writeInt32LE(n & -1, 1);
+    buf.writeUInt32LE(Math.floor(n / 0x100000000), 5);
   }
 
   return buf;