diff --git a/browser.js b/browser.js
index e0ea787..b62043c 100644
--- a/browser.js
+++ b/browser.js
@@ -60,6 +60,9 @@ module.exports = function kindOf(val) {
   if (type === '[object Error]') {
     return 'error';
   }
+  if (type === '[object Promise]') {
+    return 'promise';
+  }
 
   // buffer
   if (isBuffer(val)) {
diff --git a/index.js b/index.js
index b52c291..4c0233b 100644
--- a/index.js
+++ b/index.js
@@ -59,6 +59,9 @@ module.exports = function kindOf(val) {
   if (type === '[object Error]') {
     return 'error';
   }
+  if (type === '[object Promise]') {
+    return 'promise';
+  }
 
   // buffer
   if (isBuffer(val)) {
diff --git a/test/es6/index.js b/test/es6/index.js
index 96bc93c..b074eec 100644
--- a/test/es6/index.js
+++ b/test/es6/index.js
@@ -6,6 +6,17 @@ var kindOf = require('../..');
 
 module.exports = function() {
   describe('es6 features', function() {
+    it('should work for resolved promises', function() {
+      var promise = Promise.resolve(123);
+      assert.strictEqual(kindOf(promise), 'promise');
+    });
+
+    it('should work for rejected promises', function() {
+      var promise = Promise.reject(new Error('foo bar'));
+      promise.catch(function() {})
+      assert.strictEqual(kindOf(promise), 'promise');
+    });
+
     it('should work for generators', function() {
       var gen = function * named() {return true;};
       assert.equal(kindOf(gen), 'function');