diff --git a/lib/primitives/mtx.js b/lib/primitives/mtx.js
index f370dfd5..13ce237e 100644
--- a/lib/primitives/mtx.js
+++ b/lib/primitives/mtx.js
@@ -157,6 +157,7 @@ MTX.prototype.clone = function clone() {
 
 MTX.prototype.addInput = function addInput(options, index) {
   var input = new Input();
+
   input.mutable = true;
 
   if (options instanceof TX)
@@ -240,9 +241,10 @@ MTX.prototype.scriptInput = function scriptInput(index, ring) {
   // Get the previous output's script
   prev = input.coin.script;
 
-  // This is easily the hardest part about building a transaction
-  // with segwit: figuring out where the redeem script and witness
-  // redeem scripts go.
+  // This is easily the hardest part about
+  // building a transaction with segwit:
+  // figuring out where the redeem script
+  // and witness redeem scripts go.
   if (prev.isScripthash()) {
     redeem = ring.getRedeem(prev.get(1));
 
@@ -262,6 +264,8 @@ MTX.prototype.scriptInput = function scriptInput(index, ring) {
           return false;
 
         input.witness.push(prev.toRaw());
+        input.witness.compile();
+
         input.script.push(redeem.toRaw());
         input.script.compile();
 
@@ -308,7 +312,7 @@ MTX.prototype.scriptInput = function scriptInput(index, ring) {
         return false;
 
       input.witness.push(redeem.toRaw());
-      input.script.compile();
+      input.witness.compile();
 
       return true;
     }
@@ -320,7 +324,7 @@ MTX.prototype.scriptInput = function scriptInput(index, ring) {
       if (!this.scriptVector(prev, input.witness, ring))
         return false;
 
-      input.script.compile();
+      input.witness.compile();
 
       return true;
     }