diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index 05d3cd10..16c43e67 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -308,7 +308,7 @@ TX.prototype.signatureHashV1 = function signatureHashV1(index, prev, type) {
       && (type & 0x1f) !== constants.hashType.none) {
     hashSequence = new BufferWriter();
     for (i = 0; i < this.inputs.length; i++)
-      p.writeU32(this.inputs[i].sequence);
+      hashSequence.writeU32(this.inputs[i].sequence);
     hashSequence = utils.dsha256(hashSequence.render());
   } else {
     hashSequence = utils.slice(constants.zeroHash);