diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index 32df2726..e616219d 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -785,21 +785,21 @@ TX.prototype.maxSize = function maxSize() {
   return total;
 };
 
-TX.prototype.getUnspent = function getUnspent(unspent, hardFee) {
+TX.prototype.getUnspent = function getUnspent(unspent, fee) {
   var tx = this.clone();
   var cost = tx.funds('out');
-  var fee = 1;
+  var totalkb = 1;
   var total = cost.addn(constants.tx.fee);
   var inputs = [];
   var lastAdded = 0;
-  var size, addFee, change;
+  var size, newkb, change;
 
-  if (!hardFee)
-    hardFee = this._fee;
+  if (!fee)
+    fee = this._fee;
 
-  if (hardFee) {
-    total = cost.add(hardFee);
-    this._fee = hardFee;
+  if (fee) {
+    total = cost.add(fee);
+    this._fee = fee;
   }
 
   function addInput(unspent) {
@@ -815,7 +815,7 @@ TX.prototype.getUnspent = function getUnspent(unspent, hardFee) {
   // Transfer `total` funds maximum.
   unspent.every(addInput);
 
-  if (!hardFee) {
+  if (!fee) {
     // Add dummy output (for `change`) to
     // calculate maximum TX size.
     tx.output({
@@ -829,9 +829,9 @@ TX.prototype.getUnspent = function getUnspent(unspent, hardFee) {
       // Calculate max possible size after signing.
       size = tx.maxSize();
 
-      addFee = Math.ceil(size / 1024) - fee;
-      total.iaddn(addFee * constants.tx.fee);
-      fee += addFee;
+      newkb = Math.ceil(size / 1024) - totalkb;
+      total.iaddn(newkb * constants.tx.fee);
+      totalkb += newkb;
 
       // Failed to get enough funds, add more inputs.
       if (tx.funds('in').cmp(total) < 0)
@@ -844,7 +844,7 @@ TX.prototype.getUnspent = function getUnspent(unspent, hardFee) {
 
   // Still failing to get enough funds.
   if (tx.funds('in').cmp(total) < 0)
-    return null;
+    return;
 
   // How much money is left after filling outputs.
   change = tx.funds('in').sub(total);
@@ -862,8 +862,11 @@ TX.prototype.getUnspent = function getUnspent(unspent, hardFee) {
 TX.prototype.fillUnspent = function fillUnspent(unspent, changeAddress, fee) {
   var result = this.getUnspent(unspent, fee);
 
+  if (fee)
+    this._fee = fee;
+
   if (!result)
-    return result;
+    return;
 
   this.changeAddress = changeAddress
     || this.changeAddress