diff --git a/lib/bcoin/txdb.js b/lib/bcoin/txdb.js
index 15b836fd..63dd2948 100644
--- a/lib/bcoin/txdb.js
+++ b/lib/bcoin/txdb.js
@@ -483,16 +483,15 @@ TXDB.prototype.getInfo = function getInfo(tx, callback) {
  * Add an orphan (tx hash + input index)
  * to orphan list. Stored by its required coin ID.
  * @private
- * @param {String} key - Required coin hash + index.
- * @param {Hash} hash - Orphan transaction hash.
- * @param {Number} index - Orphan input index.
+ * @param {Outpoint} prevout - Required coin hash & index.
+ * @param {Buffer} spender - Spender input hash and index.
  * @param {Function} callback - Returns [Error, Buffer].
  */
 
-TXDB.prototype._addOrphan = function _addOrphan(hash, index, outpoint, callback) {
+TXDB.prototype._addOrphan = function _addOrphan(prevout, spender, callback) {
   var self = this;
   var p = new BufferWriter();
-  var key = this.key.o(hash, index);
+  var key = this.key.o(prevout.hash, prevout.index);
 
   this.get(key, function(err, data) {
     if (err)
@@ -501,7 +500,7 @@ TXDB.prototype._addOrphan = function _addOrphan(hash, index, outpoint, callback)
     if (data)
       p.writeBytes(data);
 
-    p.writeBytes(outpoint);
+    p.writeBytes(spender);
 
     self.put(key, p.render());
 
@@ -512,7 +511,8 @@ TXDB.prototype._addOrphan = function _addOrphan(hash, index, outpoint, callback)
 /**
  * Retrieve orphan list by coin ID.
  * @private
- * @param {String} key
+ * @param {Hash} hash
+ * @param {Number} index
  * @param {Function} callback - Returns [Error, {@link Orphan}].
  */
 
@@ -767,7 +767,7 @@ TXDB.prototype.add = function add(tx, info, callback) {
       // Consume unspent money or add orphans
       utils.forEachSerial(tx.inputs, function(input, next, i) {
         var prevout = input.prevout;
-        var key, address, outpoint;
+        var key, address, spender;
 
         if (tx.isCoinbase())
           return next();
@@ -782,12 +782,12 @@ TXDB.prototype.add = function add(tx, info, callback) {
         key = prevout.hash + prevout.index;
 
         // s/[outpoint-key] -> [spender-hash]|[spender-input-index]
-        outpoint = bcoin.outpoint.fromTX(tx, i).toRaw();
-        self.put(self.key.s(prevout.hash, prevout.index), outpoint);
+        spender = bcoin.outpoint.fromTX(tx, i).toRaw();
+        self.put(self.key.s(prevout.hash, prevout.index), spender);
 
         // Add orphan, if no parent transaction is yet known
         if (!input.coin)
-          return self._addOrphan(prevout.hash, prevout.index, outpoint, next);
+          return self._addOrphan(prevout, spender, next);
 
         self.del(self.key.c(prevout.hash, prevout.index));
         self.del(self.key.C(path.account, prevout.hash, prevout.index));