diff --git a/lib/primitives/tx.js b/lib/primitives/tx.js
index 14b6ce53..6b7a3f19 100644
--- a/lib/primitives/tx.js
+++ b/lib/primitives/tx.js
@@ -735,9 +735,6 @@ TX.prototype.signatureHashV1 = function signatureHashV1(index, prev, value, type
 TX.prototype.checksig = function checksig(index, prev, value, sig, key, version) {
   var type, hash;
 
-  if (type == null)
-    type = Script.hashType.ALL;
-
   if (sig.length === 0)
     return false;
 
@@ -754,6 +751,7 @@ TX.prototype.checksig = function checksig(index, prev, value, sig, key, version)
  * (in the case of witnesspubkeyhash, this should be the generated
  * p2pkh script).
  * @param {Amount} value - Previous output value.
+ * @param {Buffer} key
  * @param {SighashType} type
  * @param {Number} version - Sighash version (0=legacy, 1=segwit).
  * @returns {Buffer} Signature in DER format.
@@ -765,6 +763,9 @@ TX.prototype.signature = function signature(index, prev, value, key, type, versi
   if (type == null)
     type = Script.hashType.ALL;
 
+  if (version == null)
+    version = 0;
+
   hash = this.signatureHash(index, prev, value, type, version);
 
   sig = ec.sign(hash, key);