diff --git a/lib/bcoin/mtx.js b/lib/bcoin/mtx.js
index 1346f37c..7523900b 100644
--- a/lib/bcoin/mtx.js
+++ b/lib/bcoin/mtx.js
@@ -684,21 +684,37 @@ MTX.prototype.scriptOutput = function scriptOutput(index, options) {
     output.script = Script.createOutputScript(options);
 };
 
-MTX.prototype.maxSize = function maxSize(maxM, maxN) {
-  var copy = this.clone();
+MTX.prototype.isScripted = function isScripted() {
+  if (this.inputs.length === 0)
+    return false;
+
+  if (this.outputs.length === 0)
+    return false;
+
+  return this.inputs.every(function(input) {
+    return input.script.code.length > 0 || input.witness.items.length > 0;
+  });
+};
+
+MTX.prototype.maxSize = function maxSize(maxM, maxN, force) {
   var i, j, input, total, size, prev, m, n, witness;
 
-  // Create copy with 0-script inputs
-  for (i = 0; i < copy.inputs.length; i++) {
-    copy.inputs[i].script = new Script([]);
-    copy.inputs[i].witness = new Witness([]);
+  if (!force && this.isScripted())
+    return this.getVirtualSize();
+
+  // Calculate the size, minus the input scripts.
+  total = bcoin.protocol.framer.tx.size(this);
+
+  for (i = 0; i < this.inputs.length; i++) {
+    input = this.inputs[i];
+    size = input.script.getSize();
+    total -= utils.sizeVarint(size) + size;
+    total += 1;
   }
 
-  total = bcoin.protocol.framer.tx.size(copy);
-
   // Add size for signatures and public keys
-  for (i = 0; i < copy.inputs.length; i++) {
-    input = copy.inputs[i];
+  for (i = 0; i < this.inputs.length; i++) {
+    input = this.inputs[i];
     size = 0;
     witness = false;
 
@@ -712,12 +728,12 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN) {
 
     // If we have access to the redeem script,
     // we can use it to calculate size much easier.
-    if (this.inputs[i].script.code.length && prev.isScripthash()) {
+    if (input.script.code.length && prev.isScripthash()) {
       // Need to add the redeem script size
       // here since it will be ignored by
       // the isMultisig clause.
       // OP_PUSHDATA2 [redeem]
-      prev = this.inputs[i].script.getRedeem();
+      prev = input.script.getRedeem();
       size += 3 + prev.getSize();
     }
 
@@ -727,8 +743,8 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN) {
       // redeem script (if there was one)
       // is now worth 4 points.
       size *= 4;
-      if (this.inputs[i].witness.items.length && prev.isWitnessScripthash()) {
-        prev = this.inputs[i].witness.getRedeem();
+      if (input.witness.items.length && prev.isWitnessScripthash()) {
+        prev = input.witness.getRedeem();
         size += 3 + prev.getSize();
       } else if (prev.isWitnessPubkeyhash()) {
         prev = Script.createPubkeyhash(prev.code[1]);
@@ -889,7 +905,7 @@ MTX.prototype.selectCoins = function selectCoins(coins, options) {
     // bytes (10000 satoshi for every 1024 bytes).
     do {
       // Calculate max possible size after signing.
-      size = tx.maxSize(options.m, options.n);
+      size = tx.maxSize(options.m, options.n, true);
 
       if (tryFree) {
         if (tx.isFree(network.height + 1, size)) {