diff --git a/lib/primitives/tx.js b/lib/primitives/tx.js
index c0841175..88628b2d 100644
--- a/lib/primitives/tx.js
+++ b/lib/primitives/tx.js
@@ -2442,12 +2442,12 @@ TX.prototype.writeWitness = function writeWitness(bw) {
   for (const output of this.outputs)
     output.toWriter(bw);
 
-  let witness = bw.written;
+  const start = bw.offset;
 
   for (const input of this.inputs)
     input.witness.toWriter(bw);
 
-  witness = bw.written - witness;
+  const witness = bw.offset - start;
 
   bw.writeU32(this.locktime);
 
diff --git a/lib/script/script.js b/lib/script/script.js
index e36340e1..434fc4f5 100644
--- a/lib/script/script.js
+++ b/lib/script/script.js
@@ -3426,7 +3426,7 @@ Script.verifyMast = function verifyMast(program, stack, output, flags, tx, index
   for (let j = 0; j < subscripts; j++) {
     const script = stack.get(-(4 + j));
     if (version === 0) {
-      if ((scripts.written + script.length) > consensus.MAX_SCRIPT_SIZE)
+      if ((scripts.offset + script.length) > consensus.MAX_SCRIPT_SIZE)
         throw new ScriptError('SCRIPT_SIZE');
     }
     scriptRoot.writeBytes(digest.hash256(script));
diff --git a/lib/utils/reader.js b/lib/utils/reader.js
index ee8a7d5e..4323c17b 100644
--- a/lib/utils/reader.js
+++ b/lib/utils/reader.js
@@ -10,6 +10,7 @@
 const assert = require('assert');
 const encoding = require('./encoding');
 const digest = require('../crypto/digest');
+const EMPTY_BUFFER = Buffer.alloc(0);
 
 /**
  * An object that allows reading of buffers in a sane manner.
@@ -144,9 +145,9 @@ BufferReader.prototype.endData = function endData(zeroCopy) {
  */
 
 BufferReader.prototype.destroy = function destroy() {
-  this.offset = null;
-  this.stack = null;
-  this.data = null;
+  this.data = EMPTY_BUFFER;
+  this.offset = 0;
+  this.stack.length = 0;
 };
 
 /**
diff --git a/lib/utils/staticwriter.js b/lib/utils/staticwriter.js
index 1c0c53d0..c90ad799 100644
--- a/lib/utils/staticwriter.js
+++ b/lib/utils/staticwriter.js
@@ -9,6 +9,7 @@
 const assert = require('assert');
 const encoding = require('./encoding');
 const digest = require('../crypto/digest');
+const EMPTY_BUFFER = Buffer.alloc(0);
 
 /**
  * Statically allocated buffer writer.
@@ -22,7 +23,7 @@ function StaticWriter(size) {
     return new StaticWriter(size);
 
   this.data = Buffer.allocUnsafe(size);
-  this.written = 0;
+  this.offset = 0;
 }
 
 /**
@@ -34,7 +35,7 @@ function StaticWriter(size) {
 StaticWriter.prototype.render = function render(keep) {
   const data = this.data;
 
-  assert(this.written === data.length);
+  assert(this.offset === data.length);
 
   if (!keep)
     this.destroy();
@@ -48,7 +49,7 @@ StaticWriter.prototype.render = function render(keep) {
  */
 
 StaticWriter.prototype.getSize = function getSize() {
-  return this.written;
+  return this.offset;
 };
 
 /**
@@ -57,7 +58,7 @@ StaticWriter.prototype.getSize = function getSize() {
  */
 
 StaticWriter.prototype.seek = function seek(offset) {
-  this.written += offset;
+  this.offset += offset;
 };
 
 /**
@@ -65,8 +66,8 @@ StaticWriter.prototype.seek = function seek(offset) {
  */
 
 StaticWriter.prototype.destroy = function destroy() {
-  this.data = null;
-  this.written = null;
+  this.data = EMPTY_BUFFER;
+  this.offset = 0;
 };
 
 /**
@@ -75,7 +76,7 @@ StaticWriter.prototype.destroy = function destroy() {
  */
 
 StaticWriter.prototype.writeU8 = function writeU8(value) {
-  this.written = this.data.writeUInt8(value, this.written, true);
+  this.offset = this.data.writeUInt8(value, this.offset, true);
 };
 
 /**
@@ -84,7 +85,7 @@ StaticWriter.prototype.writeU8 = function writeU8(value) {
  */
 
 StaticWriter.prototype.writeU16 = function writeU16(value) {
-  this.written = this.data.writeUInt16LE(value, this.written, true);
+  this.offset = this.data.writeUInt16LE(value, this.offset, true);
 };
 
 /**
@@ -93,7 +94,7 @@ StaticWriter.prototype.writeU16 = function writeU16(value) {
  */
 
 StaticWriter.prototype.writeU16BE = function writeU16BE(value) {
-  this.written = this.data.writeUInt16BE(value, this.written, true);
+  this.offset = this.data.writeUInt16BE(value, this.offset, true);
 };
 
 /**
@@ -102,7 +103,7 @@ StaticWriter.prototype.writeU16BE = function writeU16BE(value) {
  */
 
 StaticWriter.prototype.writeU32 = function writeU32(value) {
-  this.written = this.data.writeUInt32LE(value, this.written, true);
+  this.offset = this.data.writeUInt32LE(value, this.offset, true);
 };
 
 /**
@@ -111,7 +112,7 @@ StaticWriter.prototype.writeU32 = function writeU32(value) {
  */
 
 StaticWriter.prototype.writeU32BE = function writeU32BE(value) {
-  this.written = this.data.writeUInt32BE(value, this.written, true);
+  this.offset = this.data.writeUInt32BE(value, this.offset, true);
 };
 
 /**
@@ -120,7 +121,7 @@ StaticWriter.prototype.writeU32BE = function writeU32BE(value) {
  */
 
 StaticWriter.prototype.writeU64 = function writeU64(value) {
-  this.written = encoding.writeU64(this.data, value, this.written);
+  this.offset = encoding.writeU64(this.data, value, this.offset);
 };
 
 /**
@@ -129,7 +130,7 @@ StaticWriter.prototype.writeU64 = function writeU64(value) {
  */
 
 StaticWriter.prototype.writeU64BE = function writeU64BE(value) {
-  this.written = encoding.writeU64BE(this.data, value, this.written);
+  this.offset = encoding.writeU64BE(this.data, value, this.offset);
 };
 
 /**
@@ -138,7 +139,7 @@ StaticWriter.prototype.writeU64BE = function writeU64BE(value) {
  */
 
 StaticWriter.prototype.writeU64N = function writeU64N(value) {
-  this.written = encoding.writeU64N(this.data, value, this.written);
+  this.offset = encoding.writeU64N(this.data, value, this.offset);
 };
 
 /**
@@ -147,7 +148,7 @@ StaticWriter.prototype.writeU64N = function writeU64N(value) {
  */
 
 StaticWriter.prototype.writeU64BEN = function writeU64BEN(value) {
-  this.written = encoding.writeU64BEN(this.data, value, this.written);
+  this.offset = encoding.writeU64BEN(this.data, value, this.offset);
 };
 
 /**
@@ -156,7 +157,7 @@ StaticWriter.prototype.writeU64BEN = function writeU64BEN(value) {
  */
 
 StaticWriter.prototype.writeI8 = function writeI8(value) {
-  this.written = this.data.writeInt8(value, this.written, true);
+  this.offset = this.data.writeInt8(value, this.offset, true);
 };
 
 /**
@@ -165,7 +166,7 @@ StaticWriter.prototype.writeI8 = function writeI8(value) {
  */
 
 StaticWriter.prototype.writeI16 = function writeI16(value) {
-  this.written = this.data.writeInt16LE(value, this.written, true);
+  this.offset = this.data.writeInt16LE(value, this.offset, true);
 };
 
 /**
@@ -174,7 +175,7 @@ StaticWriter.prototype.writeI16 = function writeI16(value) {
  */
 
 StaticWriter.prototype.writeI16BE = function writeI16BE(value) {
-  this.written = this.data.writeInt16BE(value, this.written, true);
+  this.offset = this.data.writeInt16BE(value, this.offset, true);
 };
 
 /**
@@ -183,7 +184,7 @@ StaticWriter.prototype.writeI16BE = function writeI16BE(value) {
  */
 
 StaticWriter.prototype.writeI32 = function writeI32(value) {
-  this.written = this.data.writeInt32LE(value, this.written, true);
+  this.offset = this.data.writeInt32LE(value, this.offset, true);
 };
 
 /**
@@ -192,7 +193,7 @@ StaticWriter.prototype.writeI32 = function writeI32(value) {
  */
 
 StaticWriter.prototype.writeI32BE = function writeI32BE(value) {
-  this.written = this.data.writeInt32BE(value, this.written, true);
+  this.offset = this.data.writeInt32BE(value, this.offset, true);
 };
 
 /**
@@ -201,7 +202,7 @@ StaticWriter.prototype.writeI32BE = function writeI32BE(value) {
  */
 
 StaticWriter.prototype.writeI64 = function writeI64(value) {
-  this.written = encoding.writeI64(this.data, value, this.written);
+  this.offset = encoding.writeI64(this.data, value, this.offset);
 };
 
 /**
@@ -210,7 +211,7 @@ StaticWriter.prototype.writeI64 = function writeI64(value) {
  */
 
 StaticWriter.prototype.writeI64BE = function writeI64BE(value) {
-  this.written = encoding.writeI64BE(this.data, value, this.written);
+  this.offset = encoding.writeI64BE(this.data, value, this.offset);
 };
 
 /**
@@ -219,7 +220,7 @@ StaticWriter.prototype.writeI64BE = function writeI64BE(value) {
  */
 
 StaticWriter.prototype.writeI64N = function writeI64N(value) {
-  this.written = encoding.writeI64N(this.data, value, this.written);
+  this.offset = encoding.writeI64N(this.data, value, this.offset);
 };
 
 /**
@@ -228,7 +229,7 @@ StaticWriter.prototype.writeI64N = function writeI64N(value) {
  */
 
 StaticWriter.prototype.writeI64BEN = function writeI64BEN(value) {
-  this.written = encoding.writeI64BEN(this.data, value, this.written);
+  this.offset = encoding.writeI64BEN(this.data, value, this.offset);
 };
 
 /**
@@ -237,7 +238,7 @@ StaticWriter.prototype.writeI64BEN = function writeI64BEN(value) {
  */
 
 StaticWriter.prototype.writeFloat = function writeFloat(value) {
-  this.written = this.data.writeFloatLE(value, this.written, true);
+  this.offset = this.data.writeFloatLE(value, this.offset, true);
 };
 
 /**
@@ -246,7 +247,7 @@ StaticWriter.prototype.writeFloat = function writeFloat(value) {
  */
 
 StaticWriter.prototype.writeFloatBE = function writeFloatBE(value) {
-  this.written = this.data.writeFloatBE(value, this.written, true);
+  this.offset = this.data.writeFloatBE(value, this.offset, true);
 };
 
 /**
@@ -255,7 +256,7 @@ StaticWriter.prototype.writeFloatBE = function writeFloatBE(value) {
  */
 
 StaticWriter.prototype.writeDouble = function writeDouble(value) {
-  this.written = this.data.writeDoubleLE(value, this.written, true);
+  this.offset = this.data.writeDoubleLE(value, this.offset, true);
 };
 
 /**
@@ -264,7 +265,7 @@ StaticWriter.prototype.writeDouble = function writeDouble(value) {
  */
 
 StaticWriter.prototype.writeDoubleBE = function writeDoubleBE(value) {
-  this.written = this.data.writeDoubleBE(value, this.written, true);
+  this.offset = this.data.writeDoubleBE(value, this.offset, true);
 };
 
 /**
@@ -273,7 +274,7 @@ StaticWriter.prototype.writeDoubleBE = function writeDoubleBE(value) {
  */
 
 StaticWriter.prototype.writeVarint = function writeVarint(value) {
-  this.written = encoding.writeVarint(this.data, value, this.written);
+  this.offset = encoding.writeVarint(this.data, value, this.offset);
 };
 
 /**
@@ -282,7 +283,7 @@ StaticWriter.prototype.writeVarint = function writeVarint(value) {
  */
 
 StaticWriter.prototype.writeVarintN = function writeVarintN(value) {
-  this.written = encoding.writeVarintN(this.data, value, this.written);
+  this.offset = encoding.writeVarintN(this.data, value, this.offset);
 };
 
 /**
@@ -291,7 +292,7 @@ StaticWriter.prototype.writeVarintN = function writeVarintN(value) {
  */
 
 StaticWriter.prototype.writeVarint2 = function writeVarint2(value) {
-  this.written = encoding.writeVarint2(this.data, value, this.written);
+  this.offset = encoding.writeVarint2(this.data, value, this.offset);
 };
 
 /**
@@ -300,7 +301,7 @@ StaticWriter.prototype.writeVarint2 = function writeVarint2(value) {
  */
 
 StaticWriter.prototype.writeVarint2N = function writeVarint2N(value) {
-  this.written = encoding.writeVarint2N(this.data, value, this.written);
+  this.offset = encoding.writeVarint2N(this.data, value, this.offset);
 };
 
 /**
@@ -312,9 +313,9 @@ StaticWriter.prototype.writeBytes = function writeBytes(value) {
   if (value.length === 0)
     return;
 
-  value.copy(this.data, this.written);
+  value.copy(this.data, this.offset);
 
-  this.written += value.length;
+  this.offset += value.length;
 };
 
 /**
@@ -340,8 +341,8 @@ StaticWriter.prototype.copy = function copy(value, start, end) {
   if (len === 0)
     return;
 
-  value.copy(this.data, this.written, start, end);
-  this.written += len;
+  value.copy(this.data, this.offset, start, end);
+  this.offset += len;
 };
 
 /**
@@ -356,9 +357,9 @@ StaticWriter.prototype.writeString = function writeString(value, enc) {
 
   const size = Buffer.byteLength(value, enc);
 
-  this.data.write(value, this.written, enc);
+  this.data.write(value, this.offset, enc);
 
-  this.written += size;
+  this.offset += size;
 };
 
 /**
@@ -373,8 +374,8 @@ StaticWriter.prototype.writeHash = function writeHash(value) {
     return;
   }
   assert(value.length === 64);
-  this.data.write(value, this.written, 'hex');
-  this.written += 32;
+  this.data.write(value, this.offset, 'hex');
+  this.offset += 32;
 };
 
 /**
@@ -392,9 +393,9 @@ StaticWriter.prototype.writeVarString = function writeVarString(value, enc) {
   const size = Buffer.byteLength(value, enc);
 
   this.writeVarint(size);
-  this.data.write(value, this.written, enc);
+  this.data.write(value, this.offset, enc);
 
-  this.written += size;
+  this.offset += size;
 };
 
 /**
@@ -413,10 +414,10 @@ StaticWriter.prototype.writeNullString = function writeNullString(value, enc) {
  */
 
 StaticWriter.prototype.writeChecksum = function writeChecksum() {
-  const data = this.data.slice(0, this.written);
+  const data = this.data.slice(0, this.offset);
   const hash = digest.hash256(data);
-  hash.copy(this.data, this.written, 0, 4);
-  this.written += 4;
+  hash.copy(this.data, this.offset, 0, 4);
+  this.offset += 4;
 };
 
 /**
@@ -431,8 +432,8 @@ StaticWriter.prototype.fill = function fill(value, size) {
   if (size === 0)
     return;
 
-  this.data.fill(value, this.written, this.written + size);
-  this.written += size;
+  this.data.fill(value, this.offset, this.offset + size);
+  this.offset += size;
 };
 
 /*
diff --git a/lib/utils/writer.js b/lib/utils/writer.js
index 3047a53e..96da456e 100644
--- a/lib/utils/writer.js
+++ b/lib/utils/writer.js
@@ -66,7 +66,7 @@ function BufferWriter() {
     return new BufferWriter();
 
   this.ops = [];
-  this.written = 0;
+  this.offset = 0;
 }
 
 /**
@@ -76,7 +76,7 @@ function BufferWriter() {
  */
 
 BufferWriter.prototype.render = function render(keep) {
-  const data = Buffer.allocUnsafe(this.written);
+  const data = Buffer.allocUnsafe(this.offset);
   let off = 0;
 
   for (const op of this.ops) {
@@ -195,7 +195,7 @@ BufferWriter.prototype.render = function render(keep) {
  */
 
 BufferWriter.prototype.getSize = function getSize() {
-  return this.written;
+  return this.offset;
 };
 
 /**
@@ -204,7 +204,7 @@ BufferWriter.prototype.getSize = function getSize() {
  */
 
 BufferWriter.prototype.seek = function seek(offset) {
-  this.written += offset;
+  this.offset += offset;
   this.ops.push(new WriteOp(SEEK, offset));
 };
 
@@ -214,8 +214,7 @@ BufferWriter.prototype.seek = function seek(offset) {
 
 BufferWriter.prototype.destroy = function destroy() {
   this.ops.length = 0;
-  this.ops = null;
-  this.written = null;
+  this.offset = 0;
 };
 
 /**
@@ -224,7 +223,7 @@ BufferWriter.prototype.destroy = function destroy() {
  */
 
 BufferWriter.prototype.writeU8 = function writeU8(value) {
-  this.written += 1;
+  this.offset += 1;
   this.ops.push(new WriteOp(UI8, value));
 };
 
@@ -234,7 +233,7 @@ BufferWriter.prototype.writeU8 = function writeU8(value) {
  */
 
 BufferWriter.prototype.writeU16 = function writeU16(value) {
-  this.written += 2;
+  this.offset += 2;
   this.ops.push(new WriteOp(UI16, value));
 };
 
@@ -244,7 +243,7 @@ BufferWriter.prototype.writeU16 = function writeU16(value) {
  */
 
 BufferWriter.prototype.writeU16BE = function writeU16BE(value) {
-  this.written += 2;
+  this.offset += 2;
   this.ops.push(new WriteOp(UI16BE, value));
 };
 
@@ -254,7 +253,7 @@ BufferWriter.prototype.writeU16BE = function writeU16BE(value) {
  */
 
 BufferWriter.prototype.writeU32 = function writeU32(value) {
-  this.written += 4;
+  this.offset += 4;
   this.ops.push(new WriteOp(UI32, value));
 };
 
@@ -264,7 +263,7 @@ BufferWriter.prototype.writeU32 = function writeU32(value) {
  */
 
 BufferWriter.prototype.writeU32BE = function writeU32BE(value) {
-  this.written += 4;
+  this.offset += 4;
   this.ops.push(new WriteOp(UI32BE, value));
 };
 
@@ -274,7 +273,7 @@ BufferWriter.prototype.writeU32BE = function writeU32BE(value) {
  */
 
 BufferWriter.prototype.writeU64 = function writeU64(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(UI64, value));
 };
 
@@ -284,7 +283,7 @@ BufferWriter.prototype.writeU64 = function writeU64(value) {
  */
 
 BufferWriter.prototype.writeU64BE = function writeU64BE(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(UI64BE, value));
 };
 
@@ -294,7 +293,7 @@ BufferWriter.prototype.writeU64BE = function writeU64BE(value) {
  */
 
 BufferWriter.prototype.writeU64N = function writeU64N(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(UI64N, value));
 };
 
@@ -304,7 +303,7 @@ BufferWriter.prototype.writeU64N = function writeU64N(value) {
  */
 
 BufferWriter.prototype.writeU64BEN = function writeU64BEN(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(UI64BEN, value));
 };
 
@@ -314,7 +313,7 @@ BufferWriter.prototype.writeU64BEN = function writeU64BEN(value) {
  */
 
 BufferWriter.prototype.writeI8 = function writeI8(value) {
-  this.written += 1;
+  this.offset += 1;
   this.ops.push(new WriteOp(I8, value));
 };
 
@@ -324,7 +323,7 @@ BufferWriter.prototype.writeI8 = function writeI8(value) {
  */
 
 BufferWriter.prototype.writeI16 = function writeI16(value) {
-  this.written += 2;
+  this.offset += 2;
   this.ops.push(new WriteOp(I16, value));
 };
 
@@ -334,7 +333,7 @@ BufferWriter.prototype.writeI16 = function writeI16(value) {
  */
 
 BufferWriter.prototype.writeI16BE = function writeI16BE(value) {
-  this.written += 2;
+  this.offset += 2;
   this.ops.push(new WriteOp(I16BE, value));
 };
 
@@ -344,7 +343,7 @@ BufferWriter.prototype.writeI16BE = function writeI16BE(value) {
  */
 
 BufferWriter.prototype.writeI32 = function writeI32(value) {
-  this.written += 4;
+  this.offset += 4;
   this.ops.push(new WriteOp(I32, value));
 };
 
@@ -354,7 +353,7 @@ BufferWriter.prototype.writeI32 = function writeI32(value) {
  */
 
 BufferWriter.prototype.writeI32BE = function writeI32BE(value) {
-  this.written += 4;
+  this.offset += 4;
   this.ops.push(new WriteOp(I32BE, value));
 };
 
@@ -364,7 +363,7 @@ BufferWriter.prototype.writeI32BE = function writeI32BE(value) {
  */
 
 BufferWriter.prototype.writeI64 = function writeI64(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(I64, value));
 };
 
@@ -374,7 +373,7 @@ BufferWriter.prototype.writeI64 = function writeI64(value) {
  */
 
 BufferWriter.prototype.writeI64BE = function writeI64BE(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(I64BE, value));
 };
 
@@ -384,7 +383,7 @@ BufferWriter.prototype.writeI64BE = function writeI64BE(value) {
  */
 
 BufferWriter.prototype.writeI64N = function writeI64N(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(I64N, value));
 };
 
@@ -394,7 +393,7 @@ BufferWriter.prototype.writeI64N = function writeI64N(value) {
  */
 
 BufferWriter.prototype.writeI64BEN = function writeI64BEN(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(I64BEN, value));
 };
 
@@ -404,7 +403,7 @@ BufferWriter.prototype.writeI64BEN = function writeI64BEN(value) {
  */
 
 BufferWriter.prototype.writeFloat = function writeFloat(value) {
-  this.written += 4;
+  this.offset += 4;
   this.ops.push(new WriteOp(FL, value));
 };
 
@@ -414,7 +413,7 @@ BufferWriter.prototype.writeFloat = function writeFloat(value) {
  */
 
 BufferWriter.prototype.writeFloatBE = function writeFloatBE(value) {
-  this.written += 4;
+  this.offset += 4;
   this.ops.push(new WriteOp(FLBE, value));
 };
 
@@ -424,7 +423,7 @@ BufferWriter.prototype.writeFloatBE = function writeFloatBE(value) {
  */
 
 BufferWriter.prototype.writeDouble = function writeDouble(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(DBL, value));
 };
 
@@ -434,7 +433,7 @@ BufferWriter.prototype.writeDouble = function writeDouble(value) {
  */
 
 BufferWriter.prototype.writeDoubleBE = function writeDoubleBE(value) {
-  this.written += 8;
+  this.offset += 8;
   this.ops.push(new WriteOp(DBLBE, value));
 };
 
@@ -444,7 +443,7 @@ BufferWriter.prototype.writeDoubleBE = function writeDoubleBE(value) {
  */
 
 BufferWriter.prototype.writeVarint = function writeVarint(value) {
-  this.written += encoding.sizeVarint(value);
+  this.offset += encoding.sizeVarint(value);
   this.ops.push(new WriteOp(VARINT, value));
 };
 
@@ -454,7 +453,7 @@ BufferWriter.prototype.writeVarint = function writeVarint(value) {
  */
 
 BufferWriter.prototype.writeVarintN = function writeVarintN(value) {
-  this.written += encoding.sizeVarintN(value);
+  this.offset += encoding.sizeVarintN(value);
   this.ops.push(new WriteOp(VARINTN, value));
 };
 
@@ -464,7 +463,7 @@ BufferWriter.prototype.writeVarintN = function writeVarintN(value) {
  */
 
 BufferWriter.prototype.writeVarint2 = function writeVarint2(value) {
-  this.written += encoding.sizeVarint2(value);
+  this.offset += encoding.sizeVarint2(value);
   this.ops.push(new WriteOp(VARINT2, value));
 };
 
@@ -474,7 +473,7 @@ BufferWriter.prototype.writeVarint2 = function writeVarint2(value) {
  */
 
 BufferWriter.prototype.writeVarint2N = function writeVarint2N(value) {
-  this.written += encoding.sizeVarint2N(value);
+  this.offset += encoding.sizeVarint2N(value);
   this.ops.push(new WriteOp(VARINT2N, value));
 };
 
@@ -487,7 +486,7 @@ BufferWriter.prototype.writeBytes = function writeBytes(value) {
   if (value.length === 0)
     return;
 
-  this.written += value.length;
+  this.offset += value.length;
   this.ops.push(new WriteOp(BYTES, value));
 };
 
@@ -497,13 +496,13 @@ BufferWriter.prototype.writeBytes = function writeBytes(value) {
  */
 
 BufferWriter.prototype.writeVarBytes = function writeVarBytes(value) {
-  this.written += encoding.sizeVarint(value.length);
+  this.offset += encoding.sizeVarint(value.length);
   this.ops.push(new WriteOp(VARINT, value.length));
 
   if (value.length === 0)
     return;
 
-  this.written += value.length;
+  this.offset += value.length;
   this.ops.push(new WriteOp(BYTES, value));
 };
 
@@ -530,7 +529,7 @@ BufferWriter.prototype.writeString = function writeString(value, enc) {
   if (value.length === 0)
     return;
 
-  this.written += Buffer.byteLength(value, enc);
+  this.offset += Buffer.byteLength(value, enc);
   this.ops.push(new WriteOp(STR, value, enc));
 };
 
@@ -563,8 +562,8 @@ BufferWriter.prototype.writeVarString = function writeVarString(value, enc) {
 
   const size = Buffer.byteLength(value, enc);
 
-  this.written += encoding.sizeVarint(size);
-  this.written += size;
+  this.offset += encoding.sizeVarint(size);
+  this.offset += size;
 
   this.ops.push(new WriteOp(VARINT, size));
 
@@ -587,7 +586,7 @@ BufferWriter.prototype.writeNullString = function writeNullString(value, enc) {
  */
 
 BufferWriter.prototype.writeChecksum = function writeChecksum() {
-  this.written += 4;
+  this.offset += 4;
   this.ops.push(new WriteOp(CHECKSUM));
 };
 
@@ -603,7 +602,7 @@ BufferWriter.prototype.fill = function fill(value, size) {
   if (size === 0)
     return;
 
-  this.written += size;
+  this.offset += size;
   this.ops.push(new WriteOp(FILL, value, null, size));
 };
 
diff --git a/migrate/coins-old.js b/migrate/coins-old.js
index 991cc5a7..6eda0119 100644
--- a/migrate/coins-old.js
+++ b/migrate/coins-old.js
@@ -257,7 +257,7 @@ Coins.prototype.toRaw = function toRaw() {
   // allocating a buffer. We mark the spents
   // after rendering the final buffer.
   bw.writeVarint(len);
-  const start = bw.written;
+  const start = bw.offset;
   bw.fill(0, len);
 
   // Write the compressed outputs.