diff --git a/lib/primitives/mtx.js b/lib/primitives/mtx.js
index da8831e2..b249a303 100644
--- a/lib/primitives/mtx.js
+++ b/lib/primitives/mtx.js
@@ -1220,19 +1220,16 @@ MTX.prototype.fund = co(function* fund(coins, options) {
     this.subtractFee(select.fee, select.subtractFee);
 
   // Add a change output.
-  this.addOutput({
-    address: select.changeAddress,
-    value: select.change
-  });
-
-  change = this.outputs[this.outputs.length - 1];
+  change = new Output();
+  change.value = select.change;
+  change.script.fromAddress(select.changeAddress);
 
   if (change.isDust(policy.MIN_RELAY)) {
     // Do nothing. Change is added to fee.
-    this.outputs.pop();
     this.changeIndex = -1;
     assert.equal(this.getFee(), select.fee + select.change);
   } else {
+    this.outputs.push(change);
     this.changeIndex = this.outputs.length - 1;
     assert.equal(this.getFee(), select.fee);
   }
@@ -1442,7 +1439,7 @@ function CoinSelector(tx, options) {
   this.shouldSubtract = false;
   this.subtractFee = null;
   this.height = -1;
-  this.confirmations = -1;
+  this.depth = -1;
   this.hardFee = -1;
   this.rate = MTX.MIN_FEE;
   this.maxFee = -1;
@@ -1484,7 +1481,13 @@ CoinSelector.prototype.fromOptions = function fromOptions(options) {
   if (options.confirmations != null) {
     assert(util.isNumber(options.confirmations));
     assert(options.confirmations >= -1);
-    this.confirmations = options.confirmations;
+    this.depth = options.confirmations;
+  }
+
+  if (options.depth != null) {
+    assert(util.isNumber(options.depth));
+    assert(options.depth >= -1);
+    this.depth = options.depth;
   }
 
   if (options.hardFee != null) {
@@ -1597,9 +1600,9 @@ CoinSelector.prototype.isSpendable = function isSpendable(coin) {
       return false;
   }
 
-  if (this.confirmations > 0) {
+  if (this.depth > 0) {
     if (coin.height === -1)
-      return this.confirmations <= 0;
+      return this.depth <= 0;
 
     conf = this.height - coin.height;
 
@@ -1608,7 +1611,7 @@ CoinSelector.prototype.isSpendable = function isSpendable(coin) {
 
     conf += 1;
 
-    if (conf < this.confirmations)
+    if (conf < this.depth)
       return false;
   }
 
@@ -1676,7 +1679,7 @@ CoinSelector.prototype.select = co(function* select(coins) {
   if (this.hardFee !== -1)
     this.selectHard(this.hardFee);
   else
-    yield this.selectEstimate(MTX.MIN_FEE);
+    yield this.selectEstimate();
 
   if (!this.isFull()) {
     // Still failing to get enough funds.
@@ -1694,28 +1697,29 @@ CoinSelector.prototype.select = co(function* select(coins) {
 
 /**
  * Initialize selection based on size estimate.
- * @param {Amount} fee
  */
 
-CoinSelector.prototype.selectEstimate = co(function* selectEstimate(fee) {
+CoinSelector.prototype.selectEstimate = co(function* selectEstimate() {
+  var output = new Output();
   var size;
 
   // Initial fee.
-  this.fee = fee;
+  this.fee = MTX.MIN_FEE;
 
   // Transfer `total` funds maximum.
   this.fund();
 
   // Add dummy output (for `change`) to
   // calculate maximum TX size.
-  this.tx.addOutput({
+  if (this.changeAddress) {
+    output.script.fromAddress(this.changeAddress);
+  } else {
     // In case we don't have a change address,
-    // use a fake p2pkh output to gauge size.
-    script: this.changeAddress
-      ? Script.fromAddress(this.changeAddress)
-      : Script.fromPubkeyhash(encoding.ZERO_HASH160),
-    value: 0
-  });
+    // we use a fake p2pkh output to gauge size.
+    output.script.fromPubkeyhash(encoding.ZERO_HASH160);
+  }
+
+  this.tx.outputs.push(output);
 
   // Keep recalculating fee and funding
   // until we reach some sort of equilibrium.
diff --git a/lib/wallet/wallet.js b/lib/wallet/wallet.js
index c54c0613..f7b62282 100644
--- a/lib/wallet/wallet.js
+++ b/lib/wallet/wallet.js
@@ -1434,7 +1434,7 @@ Wallet.prototype._fund = co(function* fund(tx, options) {
   yield tx.fund(coins, {
     selection: options.selection,
     round: options.round,
-    confirmations: options.confirmations,
+    depth: options.confirmations,
     hardFee: options.hardFee,
     subtractFee: options.subtractFee,
     changeAddress: account.change.getAddress(),