diff --git a/lib/base58check.js b/lib/base58check.js
index d211c39..9bc78ee 100644
--- a/lib/base58check.js
+++ b/lib/base58check.js
@@ -1,10 +1,16 @@
 var base58 = require('./base58');
 var sha256sha256 = require('./hash').sha256sha256;
 
-var Base58Check = function Base58Check(buf) {
+var Base58Check = function Base58Check(obj) {
   if (!(this instanceof Base58Check))
-    return new Base58Check(buf);
-  this.buf = buf;
+    return new Base58Check(obj);
+  if (obj)
+    this.set(obj);
+};
+
+Base58Check.prototype.set = function(obj) {
+  this.buf = obj.buf || this.buf || undefined;
+  return this;
 };
 
 Base58Check.decode = function(s) {
diff --git a/test/test.base58check.js b/test/test.base58check.js
index 58e2bb6..635198c 100644
--- a/test/test.base58check.js
+++ b/test/test.base58check.js
@@ -16,6 +16,14 @@ describe('Base58Check', function() {
     should.exist(b58);
   });
 
+  describe('#set', function() {
+    
+    it('should set a buf', function() {
+      should.exist(Base58Check().set({buf: buf}).buf);
+    });
+
+  });
+
   describe('@encode', function() {
 
     it('should encode the buffer accurately', function() {
@@ -83,7 +91,7 @@ describe('Base58Check', function() {
   describe('#toBuffer', function() {
 
     it('should return the buffer', function() {
-      var b58 = Base58Check(buf);
+      var b58 = Base58Check({buf: buf});
       b58.buf.toString('hex').should.equal(buf.toString('hex'));
     });
 
@@ -92,7 +100,7 @@ describe('Base58Check', function() {
   describe('#toString', function() {
 
     it('should return the buffer', function() {
-      var b58 = Base58Check(buf);
+      var b58 = Base58Check({buf: buf});
       b58.toString().should.equal(enc);
     });