diff --git a/lib/bcoin/tx.js b/lib/bcoin/tx.js
index 2a3b7907..43e3fb08 100644
--- a/lib/bcoin/tx.js
+++ b/lib/bcoin/tx.js
@@ -597,11 +597,12 @@ TX.prototype.signatureHash = function signatureHash(index, s, type) {
     type = constants.hashType[type];
 
   assert(type != null);
+  assert(index < copy.inputs.length)
 
   // bitcoind used to return 1 as an error code:
   // it ended up being treated like a hash.
-  if (index >= copy.inputs.length)
-    return constants.oneHash.slice();
+  // if (index >= copy.inputs.length)
+  //   return constants.oneHash.slice();
 
   copy.inputs.forEach(function(input, i) {
     input.script = i === index ? s : [];