diff --git a/directly.js b/directly.js
index f04cbdc..b58bac9 100644
--- a/directly.js
+++ b/directly.js
@@ -1,70 +1,64 @@
 'use strict';
 
-require('es6-promise').polyfill();
-
 var Directly = function (concurrence, funcs) {
+
+	if (!Promise) {
+		throw 'Directly requires es6 Promises';
+	}
+
 	if (!(this instanceof Directly)) {
 		return new Directly(concurrence, funcs).run();
 	}
 	this.results = [];
 	this.concurrence = concurrence;
 	this.funcs = funcs;
-	this.counter = 0;
+	this.competitors = [];
 };
 
 Directly.prototype.run = function () {
+
 	if (this.funcs.length <= this.concurrence) {
 		return Promise.all(this.funcs.map(function (func) {
 			return func();
 		}));
 	}
-	this.competitors = [];
-	this.promise = new Promise(function (resolve, reject) {
-		this.resolve = resolve;
-		this.reject = reject;
-	}.bind(this));
-
-	var i = this.concurrence;
 
-	while (i--) {
+	while (this.concurrence--) {
 		this.executeOne();
 	}
 	this.startRace();
 
-	return this.promise;
+	return new Promise(function (resolve, reject) {
+		this.resolve = resolve;
+		this.reject = reject;
+	}.bind(this));
 };
 
 Directly.prototype.executeOne = function () {
 	var promise = this.funcs.shift()();
+	var competitors = this.competitors;
 
 	this.results.push(promise);
-	var index = this.counter++;
-	promise = promise.then(function () {
-		return index;
+	competitors.push(promise);
+
+	promise.then(function () {
+		competitors.splice(competitors.indexOf(promise), 1);
 	});
-	promise.__index = index;
-	this.competitors.push(promise);
 };
 
 Directly.prototype.startRace = function () {
 	Promise.race(this.competitors)
 		.then(function (index) {
 			if (!this.funcs.length) {
-				Promise.all(this.results)
-					.then(function (results) {
-						this.resolve(results);
-					}.bind(this));
-			} else {
-				this.competitors = this.competitors.filter(function (promise) {
-					return promise.__index !== index;
-				});
-				this.executeOne();
-				this.startRace();
+				return this.resolve(Promise.all(this.results));
 			}
+
+			this.executeOne();
+			this.startRace();
+
 		}.bind(this), function (err) {
 			this.reject(err);
 		}.bind(this));
 };
 
-
 module.exports = Directly;
diff --git a/package.json b/package.json
index b96ac72..b969163 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "directly",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "description": "Like Promise.all, only less so",
   "main": "directly.js",
   "scripts": {
@@ -24,10 +24,11 @@
   },
   "homepage": "https://github.com/wheresrhys/directly",
   "devDependencies": {
+    "es6-promise": "^2.3.0",
     "chai": "^3.2.0",
     "mocha": "^2.2.5"
   },
   "dependencies": {
-    "es6-promise": "^2.3.0"
+
   }
 }
diff --git a/test/directly.test.js b/test/directly.test.js
index e4ae5d0..ed77cda 100644
--- a/test/directly.test.js
+++ b/test/directly.test.js
@@ -1,5 +1,7 @@
 'use strict';
 
+require('es6-promise').polyfill();
+
 var expect = require('chai').expect;
 var Directly = require('../directly');