diff --git a/lib/key.js b/lib/key.js
index d7baf4a..bf4ad94 100644
--- a/lib/key.js
+++ b/lib/key.js
@@ -17,6 +17,12 @@ Key.prototype.set = function(obj) {
   return this;
 };
 
+Key.prototype.fromPrivkey = function(privkey) {
+  this.privkey = privkey;
+  this.privkey2pubkey();
+  return this;
+};
+
 Key.prototype.fromRandom = function() {
   this.privkey = Privkey().fromRandom();
   this.privkey2pubkey();
diff --git a/test/test.key.js b/test/test.key.js
index 488237f..a321c44 100644
--- a/test/test.key.js
+++ b/test/test.key.js
@@ -30,6 +30,14 @@ describe('Key', function() {
 
   });
 
+  describe("#fromPrivkey", function() {
+    
+    it('should make a new key from a privkey', function() {
+      should.exist(Key().fromPrivkey(Privkey().fromRandom()).pubkey);
+    });
+
+  });
+
   describe("#fromRandom", function() {
     
     it('should make a new priv and pub, should be compressed, mainnet', function() {