diff --git a/lib/bcoin/hd.js b/lib/bcoin/hd.js
index 76e84790..ce0f85b0 100644
--- a/lib/bcoin/hd.js
+++ b/lib/bcoin/hd.js
@@ -382,7 +382,7 @@ HD.parsePath = function parsePath(path, max) {
     if (!/^\d+$/.test(index))
       throw new Error('Non-number path index.');
 
-    index = parseInt(index, 10);
+    index = +index;
 
     if (hardened)
       index += constants.hd.HARDENED;
diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index 04625d4c..e1820fc4 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -1329,7 +1329,7 @@ utils.nonce = function _nonce() {
  */
 
 utils.readU8 = function readU8(data, off) {
-  off >>>= 0;
+  off = off >>> 0;
   return data[off];
 };
 
@@ -1341,7 +1341,7 @@ utils.readU8 = function readU8(data, off) {
  */
 
 utils.readU16 = function readU16(data, off) {
-  off >>>= 0;
+  off = off >>> 0;
   return data[off] | (data[off + 1] << 8);
 };
 
@@ -1353,7 +1353,7 @@ utils.readU16 = function readU16(data, off) {
  */
 
 utils.readU16BE = function readU16BE(data, off) {
-  off >>>= 0;
+  off = off >>> 0;
   return (data[off] << 8) | data[off + 1];
 };
 
@@ -1365,7 +1365,7 @@ utils.readU16BE = function readU16BE(data, off) {
  */
 
 utils.readU32 = function readU32(data, off) {
-  off >>>= 0;
+  off = off >>> 0;
 
   return ((data[off])
     | (data[off + 1] << 8)
@@ -1381,7 +1381,7 @@ utils.readU32 = function readU32(data, off) {
  */
 
 utils.readU32BE = function readU32BE(data, off) {
-  off >>>= 0;
+  off = off >>> 0;
 
   return (data[off] * 0x1000000)
     + ((data[off + 1] << 16)
@@ -1398,7 +1398,7 @@ utils.readU32BE = function readU32BE(data, off) {
 
 utils.readU64 = function readU64(data, off) {
   var num;
-  off >>>= 0;
+  off = off >>> 0;
   num = data.slice(off, off + 8);
   return new bn(num, 'le');
 };
@@ -1412,7 +1412,7 @@ utils.readU64 = function readU64(data, off) {
 
 utils.readU64BE = function readU64BE(data, off) {
   var num;
-  off >>>= 0;
+  off = off >>> 0;
   num = data.slice(off, off + 8);
   return new bn(num, 'be');
 };
@@ -1426,7 +1426,7 @@ utils.readU64BE = function readU64BE(data, off) {
 
 utils.read8 = function read8(data, off) {
   var num;
-  off >>>= 0;
+  off = off >>> 0;
   num = data[off];
   return !(num & 0x80) ? num : (0xff - num + 1) * -1;
 };
@@ -1440,7 +1440,7 @@ utils.read8 = function read8(data, off) {
 
 utils.read16 = function read16(data, off) {
   var num;
-  off >>>= 0;
+  off = off >>> 0;
   num = data[off] | (data[off + 1] << 8);
   return (num & 0x8000) ? num | 0xffff0000 : num;
 };
@@ -1454,7 +1454,7 @@ utils.read16 = function read16(data, off) {
 
 utils.read16BE = function read16BE(data, off) {
   var num;
-  off >>>= 0;
+  off = off >>> 0;
   num = data[off + 1] | (data[off] << 8);
   return (num & 0x8000) ? num | 0xffff0000 : num;
 };
@@ -1467,7 +1467,7 @@ utils.read16BE = function read16BE(data, off) {
  */
 
 utils.read32 = function read32(data, off) {
-  off >>>= 0;
+  off = off >>> 0;
 
   return (data[off])
     | (data[off + 1] << 8)
@@ -1483,7 +1483,7 @@ utils.read32 = function read32(data, off) {
  */
 
 utils.read32BE = function read32BE(data, off) {
-  off >>>= 0;
+  off = off >>> 0;
 
   return (data[off] << 24)
     | (data[off + 1] << 16)
@@ -1501,7 +1501,7 @@ utils.read32BE = function read32BE(data, off) {
 utils.read64 = function read64(data, off) {
   var num;
 
-  off >>>= 0;
+  off = off >>> 0;
 
   num = data.slice(off, off + 8);
 
@@ -1521,7 +1521,7 @@ utils.read64 = function read64(data, off) {
 utils.read64BE = function read64BE(data, off) {
   var num;
 
-  off >>>= 0;
+  off = off >>> 0;
 
   num = data.slice(off, off + 8);
 
@@ -1537,7 +1537,8 @@ utils.read64BE = function read64BE(data, off) {
  */
 
 utils.writeU8 = function writeU8(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = num & 0xff;
   return 1;
 };
@@ -1548,7 +1549,8 @@ utils.writeU8 = function writeU8(dst, num, off) {
  */
 
 utils.writeU16 = function writeU16(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = num & 0xff;
   dst[off + 1] = (num >>> 8) & 0xff;
   return 2;
@@ -1560,7 +1562,8 @@ utils.writeU16 = function writeU16(dst, num, off) {
  */
 
 utils.writeU16BE = function write16BE(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = (num >>> 8) & 0xff;
   dst[off + 1] = num & 0xff;
   return 2;
@@ -1572,7 +1575,8 @@ utils.writeU16BE = function write16BE(dst, num, off) {
  */
 
 utils.writeU32 = function writeU32(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off + 3] = (num >>> 24) & 0xff;
   dst[off + 2] = (num >>> 16) & 0xff;
   dst[off + 1] = (num >>> 8) & 0xff;
@@ -1586,7 +1590,8 @@ utils.writeU32 = function writeU32(dst, num, off) {
  */
 
 utils.writeU32BE = function writeU32BE(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = (num >>> 24) & 0xff;
   dst[off + 1] = (num >>> 16) & 0xff;
   dst[off + 2] = (num >>> 8) & 0xff;
@@ -1660,7 +1665,7 @@ utils.write64N = function write64N(dst, num, off, be) {
 
   assert(typeof num === 'number');
 
-  off >>>= 0;
+  off = off >>> 0;
 
   negative = num < 0;
 
@@ -1724,7 +1729,7 @@ utils.write64NBE = function write64NBE(dst, num, off) {
 utils.readU64N = function readU64N(data, off, force53, be) {
   var hi, lo;
 
-  off >>>= 0;
+  off = off >>> 0;
 
   if (be) {
     hi = utils.readU32(data, off);
@@ -1767,7 +1772,7 @@ utils.readU64NBE = function readU64NBE(data, off, force53) {
 utils.read64N = function read64N(data, off, force53, be) {
   var hi, lo;
 
-  off >>>= 0;
+  off = off >>> 0;
 
   if (be) {
     hi = utils.readU32(data, off);
@@ -1867,7 +1872,8 @@ utils.read53BE = function read53BE(data, off) {
  */
 
 utils.write8 = function write8(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = num & 0xff;
   return 1;
 };
@@ -1881,7 +1887,8 @@ utils.write8 = function write8(dst, num, off) {
  */
 
 utils.write16 = function write16(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = num & 0xff;
   dst[off + 1] = (num >>> 8) & 0xff;
   return 2;
@@ -1896,7 +1903,8 @@ utils.write16 = function write16(dst, num, off) {
  */
 
 utils.write16BE = function write16BE(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = (num >>> 8) & 0xff;
   dst[off + 1] = num & 0xff;
   return 2;
@@ -1911,7 +1919,8 @@ utils.write16BE = function write16BE(dst, num, off) {
  */
 
 utils.write32 = function write32(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = num & 0xff;
   dst[off + 1] = (num >>> 8) & 0xff;
   dst[off + 2] = (num >>> 16) & 0xff;
@@ -1928,7 +1937,8 @@ utils.write32 = function write32(dst, num, off) {
  */
 
 utils.write32BE = function write32BE(dst, num, off) {
-  off >>>= 0;
+  num = +num;
+  off = off >>> 0;
   dst[off] = (num >>> 24) & 0xff;
   dst[off + 1] = (num >>> 16) & 0xff;
   dst[off + 2] = (num >>> 8) & 0xff;
@@ -1950,7 +1960,7 @@ utils.write64 = function write64(dst, num, off) {
   if (typeof num === 'number')
     return utils.write64N(dst, num, off);
 
-  off >>>= 0;
+  off = off >>> 0;
 
   if (num.isNeg())
     num = num.neg().notn(64).addn(1);
@@ -1980,7 +1990,7 @@ utils.write64BE = function write64BE(dst, num, off) {
   if (typeof num === 'number')
     return utils.write64NBE(dst, num, off);
 
-  off >>>= 0;
+  off = off >>> 0;
 
   if (num.isNeg())
     num = num.neg().notn(64).addn(1);
@@ -2007,7 +2017,7 @@ utils.write64BE = function write64BE(dst, num, off) {
 utils.readVarint = function readVarint(data, off, big) {
   var r, bytes;
 
-  off >>>= 0;
+  off = off >>> 0;
 
   assert(off < data.length);
 
@@ -2051,7 +2061,7 @@ utils.readVarint = function readVarint(data, off, big) {
  */
 
 utils.writeVarint = function writeVarint(dst, num, off) {
-  off >>>= 0;
+  off = off >>> 0;
 
   if (bn.isBN(num)) {
     if (num.bitLength() > 32) {
@@ -2062,6 +2072,8 @@ utils.writeVarint = function writeVarint(dst, num, off) {
     num = num.toNumber();
   }
 
+  num = +num;
+
   if (num < 0xfd) {
     dst[off] = num & 0xff;
     return 1;