diff --git a/lib/privkey.js b/lib/privkey.js
index e102bf3..c0fc0d6 100644
--- a/lib/privkey.js
+++ b/lib/privkey.js
@@ -4,11 +4,15 @@ var constants = require('./constants');
 var base58check = require('./base58check');
 var Random = require('./random');
 
-var Privkey = function Privkey(obj) {
+var Privkey = function Privkey(bn) {
   if (!(this instanceof Privkey))
     return new Privkey(obj);
-  if (obj)
+  if (bn instanceof BN)
+    this.bn = bn;
+  else if (bn) {
+    var obj = bn;
     this.set(obj);
+  }
 };
 
 Privkey.prototype.set = function(obj) {
diff --git a/test/privkey.js b/test/privkey.js
index 24f9568..f9cb48e 100644
--- a/test/privkey.js
+++ b/test/privkey.js
@@ -17,6 +17,12 @@ describe('Privkey', function() {
     should.exist(privkey);
   });
 
+  it('should create a 0 private key with this convenience method', function() {
+    var bn = BN(0);
+    var privkey = new Privkey(bn);
+    privkey.bn.toString().should.equal(bn.toString());
+  });
+
   it('should create a mainnet private key', function() {
     var privkey = new Privkey({bn: BN.fromBuffer(buf), networkstr: 'mainnet', compressed: true});
     privkey.toString().should.equal(encmainnet);