diff --git a/lib/signature.js b/lib/signature.js
index 31ef75ad4..c409d0490 100644
--- a/lib/signature.js
+++ b/lib/signature.js
@@ -4,7 +4,7 @@ var Pubkey = require('./pubkey');
 
 var Signature = function Signature(r, s) {
   if (!(this instanceof Signature))
-    return new Signature(obj);
+    return new Signature(r, s);
   if (r instanceof BN) {
     this.set({
       r: r,