diff --git a/lib/bcoin/script.js b/lib/bcoin/script.js
index 399ce241..c6d1e7a2 100644
--- a/lib/bcoin/script.js
+++ b/lib/bcoin/script.js
@@ -1073,7 +1073,7 @@ script.isMultisigInput = function isMultisigInput(s, pubs, tx, i) {
     return false;
 
   for (i = 1; i < s.length; i++) {
-    // res = Array.isArray(s[i]) && script.isValidSig(s[i]);
+    // res = script.isValidSig(s[i]);
     res = Array.isArray(s[i]) && 9 <= s[i].length && s[i].length <= 73;
     if (!res)
       return false;
@@ -1097,7 +1097,7 @@ script.isScripthashInput = function isScripthashInput(s, redeem) {
     return false;
 
   for (i = 1; i < s.length - 1; i++) {
-    // res = Array.isArray(s[i]) && script.isValidSig(s[i]);
+    // res = script.isValidSig(s[i]);
     res = Array.isArray(s[i]) && 9 <= s[i].length && s[i].length <= 73;
     if (!res)
       return false;
@@ -1126,7 +1126,7 @@ script.isScripthashInput = function isScripthashInput(s, redeem) {
  *
  * This function is consensus-critical since BIP66.
  */
-script.isValidSig = function(sig) {
+script.isValidSig = function(sig, allowZero) {
   var lenR, lenS;
 
   if (!Array.isArray(sig))
@@ -1134,7 +1134,7 @@ script.isValidSig = function(sig) {
 
   // Empty signature. Not strictly DER encoded, but allowed to provide a
   // compact way to provide an invalid signature for use with CHECK(MULTI)SIG
-  if (sig.length === 0)
+  if (allowZero && sig.length === 0)
     return true;
 
   // Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S] [sighash]