diff --git a/lib/keypair.js b/lib/keypair.js
index e47e540..1515769 100644
--- a/lib/keypair.js
+++ b/lib/keypair.js
@@ -3,32 +3,32 @@ var Pubkey = require('./pubkey');
 var BN = require('./bn');
 var point = require('./point');
 
-var Key = function Key(obj) {
-  if (!(this instanceof Key))
-    return new Key(obj);
+var Keypair = function Keypair(obj) {
+  if (!(this instanceof Keypair))
+    return new Keypair(obj);
   if (obj)
     this.set(obj);
 };
 
-Key.prototype.set = function(obj) {
+Keypair.prototype.set = function(obj) {
   this.privkey = obj.privkey || this.privkey || undefined;
   this.pubkey = obj.pubkey || this.pubkey || undefined;
   return this;
 };
 
-Key.prototype.fromPrivkey = function(privkey) {
+Keypair.prototype.fromPrivkey = function(privkey) {
   this.privkey = privkey;
   this.privkey2pubkey();
   return this;
 };
 
-Key.prototype.fromRandom = function() {
+Keypair.prototype.fromRandom = function() {
   this.privkey = Privkey().fromRandom();
   this.privkey2pubkey();
   return this;
 };
 
-Key.prototype.fromString = function(str) {
+Keypair.prototype.fromString = function(str) {
   var obj = JSON.parse(str);
   if (obj.privkey) {
     this.privkey = new Privkey();
@@ -40,11 +40,11 @@ Key.prototype.fromString = function(str) {
   }
 };
 
-Key.prototype.privkey2pubkey = function() {
+Keypair.prototype.privkey2pubkey = function() {
   this.pubkey = Pubkey().fromPrivkey(this.privkey);
 };
 
-Key.prototype.toString = function() {
+Keypair.prototype.toString = function() {
   var obj = {};
   if (this.privkey)
     obj.privkey = this.privkey.toString();
@@ -53,4 +53,4 @@ Key.prototype.toString = function() {
   return JSON.stringify(obj);
 };
 
-module.exports = Key;
+module.exports = Keypair;