diff --git a/lib/bcoin/input.js b/lib/bcoin/input.js
index ffb7ba9b..08f2656c 100644
--- a/lib/bcoin/input.js
+++ b/lib/bcoin/input.js
@@ -205,6 +205,9 @@ function Input(options) {
   this.coin = null;
   this.mutable = false;
 
+  this._type = null;
+  this._address = null;
+
   if (options)
     this.fromOptions(options);
 }
@@ -217,9 +220,9 @@ function Input(options) {
 
 Input.prototype.fromOptions = function fromOptions(options) {
   assert(options, 'Input data is required.');
+  assert(options.prevout);
 
-  if (options.prevout)
-    this.prevout.fromOptions(options.prevout);
+  this.prevout.fromOptions(options.prevout);
 
   if (options.script)
     this.script.fromOptions(options.script);
diff --git a/lib/bcoin/mtx.js b/lib/bcoin/mtx.js
index 1106d605..8248151e 100644
--- a/lib/bcoin/mtx.js
+++ b/lib/bcoin/mtx.js
@@ -150,30 +150,63 @@ MTX.prototype.clone = function clone() {
  */
 
 MTX.prototype.addInput = function addInput(options, index) {
-  var input;
-
-  if (options instanceof TX)
-    options = bcoin.coin.fromTX(options, index);
-
-  if (options instanceof bcoin.coin) {
-    assert(typeof options.hash === 'string');
-    assert(typeof options.index === 'number');
-    options = {
-      prevout: { hash: options.hash, index: options.index },
-      coin: options
-    };
-  }
-
-  assert(options.prevout);
-
-  input = new bcoin.input(options);
+  var input = new bcoin.input();
   input.mutable = true;
 
+  if (options instanceof TX)
+    input.fromTX(options, index);
+  else if (options instanceof bcoin.coin)
+    input.fromCoin(options);
+  else
+    input.fromOptions(options);
+
   this.inputs.push(input);
 
   return this;
 };
 
+/**
+ * Add an output.
+ * @example
+ * tx.addOutput({ address: ..., value: 100000 });
+ * tx.addOutput({ address: ..., value: utils.satoshi('0.1') });
+ * tx.addOutput(receivingWallet, utils.satoshi('0.1'));
+ * @param {Wallet|KeyRing|Object} obj - Wallet, Address,
+ * or options (see {@link Script.createOutputScript} for options).
+ * @param {Amount?} value - Only needs to be present for non-options.
+ */
+
+MTX.prototype.addOutput = function addOutput(options, value) {
+  var options, output;
+
+  if ((options instanceof bcoin.wallet)
+      || (options instanceof bcoin.keyring)) {
+    options = options.getAddress();
+  }
+
+  if (typeof options === 'string')
+    options = bcoin.address.fromBase58(options);
+
+  if (options instanceof bcoin.address)
+    options = Script.fromAddress(options);
+
+  output = new bcoin.output();
+  output.mutable = true;
+
+  if (options instanceof Script) {
+    assert(utils.isNumber(value));
+    assert(value >= 0);
+    output.script.fromOptions(options);
+    output.value = value;
+  } else {
+    output.fromOptions(options);
+  }
+
+  this.outputs.push(output);
+
+  return this;
+};
+
 /**
  * Build input script (or witness) templates (with
  * OP_0 in place of signatures).
@@ -698,48 +731,6 @@ MTX.prototype.sign = function sign(index, addr, key, type) {
   return true;
 };
 
-/**
- * Add an output.
- * @example
- * tx.addOutput({ address: ..., value: new bn(100000) });
- * tx.addOutput({ address: ..., value: utils.satoshi('0.1') });
- * tx.addOutput(receivingWallet, utils.satoshi('0.1'));
- * @param {Wallet|KeyRing|Object} obj - Wallet, Address,
- * or options (see {@link Script.createOutputScript} for options).
- * @param {Amount?} value - Only needs to be present for non-options.
- */
-
-MTX.prototype.addOutput = function addOutput(address, value) {
-  var options, output;
-
-  if ((address instanceof bcoin.wallet)
-      || (address instanceof bcoin.keyring)) {
-    address = address.getAddress();
-  }
-
-  if (typeof address === 'string')
-    address = bcoin.address.fromBase58(address);
-
-  if (address instanceof bcoin.address) {
-    options = {
-      address: address,
-      value: value
-    };
-  } else {
-    options = address;
-  }
-
-  output = new bcoin.output(options);
-  output.mutable = true;
-
-  if (options.address)
-    output.script = Script.fromAddress(options.address);
-
-  this.outputs.push(output);
-
-  return this;
-};
-
 /**
  * Test whether the transaction at least
  * has all script templates built.
diff --git a/lib/bcoin/output.js b/lib/bcoin/output.js
index d02d1709..00b5e9d5 100644
--- a/lib/bcoin/output.js
+++ b/lib/bcoin/output.js
@@ -32,6 +32,9 @@ function Output(options) {
   this.script = new bcoin.script();
   this.mutable = false;
 
+  this._type = null;
+  this._address = null;
+
   if (options)
     this.fromOptions(options);
 }
@@ -44,14 +47,19 @@ function Output(options) {
 
 Output.prototype.fromOptions = function fromOptions(options) {
   assert(options, 'Output data is required.');
-  assert(!options.value || utils.isNumber(options.value));
 
-  if (options.value)
+  if (options.value) {
+    assert(utils.isNumber(options.value));
+    assert(options.value >= 0);
     this.value = options.value;
+  }
 
   if (options.script)
     this.script.fromOptions(options.script);
 
+  if (options.address)
+    this.script = bcoin.script.fromAddress(options.address);
+
   return this;
 };