diff --git a/package.json b/package.json
index 6403a3eec6..b3f6a16acd 100644
--- a/package.json
+++ b/package.json
@@ -98,6 +98,7 @@
   },
   "devDependencies": {
     "chai": "^3.4.0",
+    "chai-as-promised": "^5.1.0",
     "coffee-coverage": "~0.4.2",
     "coveralls": "^2.11.2",
     "csv": "~0.3.6",
diff --git a/test/api/register/POST-register.test.js b/test/api/register/POST-register.test.js
index e8e970cf44..a932aa4b2e 100644
--- a/test/api/register/POST-register.test.js
+++ b/test/api/register/POST-register.test.js
@@ -1,31 +1,83 @@
-import {requester} from '../../helpers/api.helper';
+import {
+  generateUser,
+  requester,
+} from '../../helpers/api.helper';
 import {v4 as generateRandomUserName} from 'uuid';
 
 describe('POST /register', () => {
-  let api;
 
-  beforeEach(() => {
-    api = requester();
+  context('username and email are free', () => {
+    it('registers a new user', (done) => {
+      let api = requester();
+      let username = generateRandomUserName();
+      let email = `${username}@example.com`;
+      let password = 'password';
+
+      api.post('/register', {
+        username:        username,
+        email:           email,
+        password:        password,
+        confirmPassword: password,
+      }).then((user) => {
+        expect(user._id).to.exist;
+        expect(user.apiToken).to.exist;
+        expect(user.auth.local.username).to.eql(username);
+        done();
+      });
+    });
+
+    it('requires password and confirmPassword to match', () => {
+      let api = requester();
+      let username = generateRandomUserName();
+      let email = `${username}@example.com`;
+      let password = 'password';
+      let confirmPassword = 'not password';
+
+      return expect(api.post('/register', {
+        username:        username,
+        email:           email,
+        password:        password,
+        confirmPassword: confirmPassword,
+      })).to.be.rejectedWith(':password and :confirmPassword don\'t match');
+    });
   });
 
-  it('registers a new user', (done) => {
-    let username = generateRandomUserName();
-    let email = `${username}@example.com`;
-    let password = 'password';
+  context('login is already taken', () => {
+    let username, email;
+    beforeEach(() => {
+      username = generateRandomUserName();
+      email = `${username}@example.com`;
+      return generateUser({
+        'auth.local.username': username,
+        'auth.local.lowerCaseUsername': username,
+        'auth.local.email': email
+      });
+    });
 
-    api.post('/register', {
-      username:        username,
-      email:           email,
-      password:        password,
-      confirmPassword: password,
-    }).then((user) => {
-      expect(user._id).to.exist;
-      expect(user.auth.local.username).to.eql(username);
-      expect(user.auth.local.email).to.eql(`${username}@example.com`);
-      done();
-    })
-    .catch((err) => {
-      done(err);
+    it('rejects if username is already taken', () => {
+      let api = requester();
+      let uniqueEmail = `${generateRandomUserName()}@exampe.com`;
+      let password = 'password';
+
+      return expect(api.post('/register', {
+        username:        username,
+        email:           uniqueEmail,
+        password:        password,
+        confirmPassword: password,
+      })).to.be.rejectedWith('Username already taken');
+    });
+
+    it('rejects if email is already taken', () => {
+      let api = requester();
+      let uniqueUsername = generateRandomUserName();
+      let password = 'password';
+
+      return expect(api.post('/register', {
+        username:        uniqueUsername,
+        email:           email,
+        password:        password,
+        confirmPassword: password,
+      })).to.be.rejectedWith('Email already taken');
     });
   });
 });
diff --git a/test/helpers/globals.helper.js b/test/helpers/globals.helper.js
index 892d086dc8..a731f1e8c2 100644
--- a/test/helpers/globals.helper.js
+++ b/test/helpers/globals.helper.js
@@ -5,4 +5,5 @@
 global._ = require("lodash")
 global.chai = require("chai")
 chai.use(require("sinon-chai"))
+chai.use(require("chai-as-promised"));
 global.expect = chai.expect