diff --git a/.travis.yml b/.travis.yml
index 6bc9251da..77f50b57b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,7 +11,6 @@ php:
 - 5.6
 - 7.0
 - 7.1
-- hhvm
 env:
   global:
   - secure: Bc5ZqvZ1YYpoPZNNuU2eCB8DS6vBYrAdfBtTenBs5NSxzb+Vjven4kWakbzaMvZjb/Ib7Uph7DGuOtJXpmxnvBXPLd707LZ89oFWN/yqQlZKCcm8iErvJCB5XL+/ONHj2iPdR242HJweMcat6bMCwbVWoNDidjtWMH0U2mYFy3M=
@@ -22,10 +21,11 @@ services:
 - cassandra
 before_install:
 - phpenv config-rm xdebug.ini || return 0
+- phpenv version-name | grep ^5.[3-6] && composer remove mongodb/mongodb --dev && echo "extension=mongo.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini ; true
+- phpenv version-name | grep ^7 && echo "extension=mongodb.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini ; true
 install:
-- composer install --no-interaction
+- composer install
 before_script:
 - psql -c 'create database oauth2_server_php;' -U postgres
-- phpenv version-name | grep ^5.[3-6] && echo "extension=mongo.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini ; true
 after_script:
 - php test/cleanup.php
diff --git a/composer.json b/composer.json
index b1f28c707..561699f5e 100644
--- a/composer.json
+++ b/composer.json
@@ -12,22 +12,23 @@
         }
     ],
     "homepage": "http://github.com/bshaffer/oauth2-server-php",
-    "require":{
-        "php":">=5.3.9"
-    },
     "autoload": {
         "psr-0": { "OAuth2": "src/" }
     },
-    "suggest": {
-        "predis/predis": "Required to use the Redis storage engine",
-        "thobbs/phpcassa": "Required to use the Cassandra storage engine",
-        "aws/aws-sdk-php": "~2.8 is required to use the DynamoDB storage engine",
-        "firebase/php-jwt": "~2.2 is required to use JWT features"
+    "require":{
+        "php":">=5.3.9"
     },
     "require-dev": {
         "aws/aws-sdk-php": "~2.8",
         "firebase/php-jwt": "~2.2",
         "predis/predis": "dev-master",
-        "thobbs/phpcassa": "dev-master"
+        "thobbs/phpcassa": "dev-master",
+        "mongodb/mongodb": "^1.1"
+    },
+    "suggest": {
+        "predis/predis": "Required to use Redis storage",
+        "thobbs/phpcassa": "Required to use Cassandra storage",
+        "aws/aws-sdk-php": "~2.8 is required to use DynamoDB storage",
+        "firebase/php-jwt": "~1.1 is required to use MondoDB storage"
     }
 }
diff --git a/src/OAuth2/Storage/Mongo.php b/src/OAuth2/Storage/Mongo.php
index cef35e5e9..eea06e315 100644
--- a/src/OAuth2/Storage/Mongo.php
+++ b/src/OAuth2/Storage/Mongo.php
@@ -22,6 +22,7 @@ class Mongo implements AuthorizationCodeInterface,
     UserCredentialsInterface,
     RefreshTokenInterface,
     JwtBearerInterface,
+    PublicKeyInterface,
     OpenIDAuthorizationCodeInterface
 {
     protected $db;
@@ -46,6 +47,7 @@ public function __construct($connection, $config = array())
             'refresh_token_table' => 'oauth_refresh_tokens',
             'code_table' => 'oauth_authorization_codes',
             'user_table' => 'oauth_users',
+            'key_table' => 'oauth_keys',
             'jwt_table' => 'oauth_jwt',
         ), $config);
     }
@@ -336,4 +338,55 @@ public function setJti($client_id, $subject, $audience, $expiration, $jti)
         //TODO: Needs mongodb implementation.
         throw new \Exception('setJti() for the MongoDB driver is currently unimplemented.');
     }
+
+    public function getPublicKey($client_id = null)
+    {
+        if ($client_id) {
+            $result = $this->collection('key_table')->findOne(array(
+                'client_id' => $client_id
+            ));
+            if ($result) {
+                return $result['public_key'];
+            }
+        }
+
+        $result = $this->collection('key_table')->findOne(array(
+            'client_id' => null
+        ));
+        return is_null($result) ? false : $result['public_key'];
+    }
+
+    public function getPrivateKey($client_id = null)
+    {
+        if ($client_id) {
+            $result = $this->collection('key_table')->findOne(array(
+                'client_id' => $client_id
+            ));
+            if ($result) {
+                return $result['private_key'];
+            }
+        }
+
+        $result = $this->collection('key_table')->findOne(array(
+            'client_id' => null
+        ));
+        return is_null($result) ? false : $result['private_key'];
+    }
+
+    public function getEncryptionAlgorithm($client_id = null)
+    {
+        if ($client_id) {
+            $result = $this->collection('key_table')->findOne(array(
+                'client_id' => $client_id
+            ));
+            if ($result) {
+                return $result['encryption_algorithm'];
+            }
+        }
+
+        $result = $this->collection('key_table')->findOne(array(
+            'client_id' => null
+        ));
+        return is_null($result) ? 'RS256' : $result['encryption_algorithm'];
+    }
 }
diff --git a/src/OAuth2/Storage/MongoDB.php b/src/OAuth2/Storage/MongoDB.php
new file mode 100644
index 000000000..64f740fc1
--- /dev/null
+++ b/src/OAuth2/Storage/MongoDB.php
@@ -0,0 +1,380 @@
+<?php
+
+namespace OAuth2\Storage;
+
+use MongoDB\Client;
+use MongoDB\Database;
+use OAuth2\OpenID\Storage\AuthorizationCodeInterface as OpenIDAuthorizationCodeInterface;
+
+/**
+ * Simple MongoDB storage for all storage types
+ *
+ * NOTE: This class is meant to get users started
+ * quickly. If your application requires further
+ * customization, extend this class or create your own.
+ *
+ * NOTE: Passwords are stored in plaintext, which is never
+ * a good idea.  Be sure to override this for your application
+ *
+ * @author Julien Chaumond <chaumond@gmail.com>
+ */
+class MongoDB implements AuthorizationCodeInterface,
+    UserCredentialsInterface,
+    AccessTokenInterface,
+    ClientCredentialsInterface,
+    RefreshTokenInterface,
+    JwtBearerInterface,
+    PublicKeyInterface,
+    OpenIDAuthorizationCodeInterface
+{
+    protected $db;
+    protected $config;
+
+    public function __construct($connection, $config = array())
+    {
+        if ($connection instanceof Database) {
+            $this->db = $connection;
+        } else {
+            if (!is_array($connection)) {
+                throw new \InvalidArgumentException('First argument to OAuth2\Storage\Mongo must be an instance of MongoDB\Database or a configuration array');
+            }
+            $server = sprintf('mongodb://%s:%d', $connection['host'], $connection['port']);
+            $m = new Client($server);
+            $this->db = $m->selectDatabase($connection['database']);
+        }
+        $this->config = array_merge(array(
+            'client_table' => 'oauth_clients',
+            'access_token_table' => 'oauth_access_tokens',
+            'refresh_token_table' => 'oauth_refresh_tokens',
+            'code_table' => 'oauth_authorization_codes',
+            'user_table' => 'oauth_users',
+            'jwt_table' => 'oauth_jwt',
+            'jti_table' => 'oauth_jti',
+            'scope_table'  => 'oauth_scopes',
+            'key_table'  => 'oauth_keys',
+        ), $config);
+    }
+
+    /* ClientCredentialsInterface */
+    public function checkClientCredentials($client_id, $client_secret = null)
+    {
+        if ($result = $this->collection('client_table')->findOne(array('client_id' => $client_id))) {
+            return $result['client_secret'] == $client_secret;
+        }
+        return false;
+    }
+
+    public function isPublicClient($client_id)
+    {
+        if (!$result = $this->collection('client_table')->findOne(array('client_id' => $client_id))) {
+            return false;
+        }
+        return empty($result['client_secret']);
+    }
+
+    /* ClientInterface */
+    public function getClientDetails($client_id)
+    {
+        $result = $this->collection('client_table')->findOne(array('client_id' => $client_id));
+        return is_null($result) ? false : $result;
+    }
+
+    public function setClientDetails($client_id, $client_secret = null, $redirect_uri = null, $grant_types = null, $scope = null, $user_id = null)
+    {
+        if ($this->getClientDetails($client_id)) {
+            $result = $this->collection('client_table')->updateOne(
+                array('client_id' => $client_id),
+                array('$set' => array(
+                    'client_secret' => $client_secret,
+                    'redirect_uri'  => $redirect_uri,
+                    'grant_types'   => $grant_types,
+                    'scope'         => $scope,
+                    'user_id'       => $user_id,
+                ))
+            );
+            return $result->getMatchedCount() > 0;
+        }
+        $client = array(
+            'client_id'     => $client_id,
+            'client_secret' => $client_secret,
+            'redirect_uri'  => $redirect_uri,
+            'grant_types'   => $grant_types,
+            'scope'         => $scope,
+            'user_id'       => $user_id,
+        );
+        $result = $this->collection('client_table')->insertOne($client);
+        return $result->getInsertedCount() > 0;
+    }
+
+    public function checkRestrictedGrantType($client_id, $grant_type)
+    {
+        $details = $this->getClientDetails($client_id);
+        if (isset($details['grant_types'])) {
+            $grant_types = explode(' ', $details['grant_types']);
+            return in_array($grant_type, $grant_types);
+        }
+        // if grant_types are not defined, then none are restricted
+        return true;
+    }
+
+    /* AccessTokenInterface */
+    public function getAccessToken($access_token)
+    {
+        $token = $this->collection('access_token_table')->findOne(array('access_token' => $access_token));
+        return is_null($token) ? false : $token;
+    }
+
+    public function setAccessToken($access_token, $client_id, $user_id, $expires, $scope = null)
+    {
+        // if it exists, update it.
+        if ($this->getAccessToken($access_token)) {
+            $result = $this->collection('access_token_table')->updateOne(
+                array('access_token' => $access_token),
+                array('$set' => array(
+                    'client_id' => $client_id,
+                    'expires' => $expires,
+                    'user_id' => $user_id,
+                    'scope' => $scope
+                ))
+            );
+            return $result->getMatchedCount() > 0;
+        }
+        $token = array(
+            'access_token' => $access_token,
+            'client_id' => $client_id,
+            'expires' => $expires,
+            'user_id' => $user_id,
+            'scope' => $scope
+        );
+        $result = $this->collection('access_token_table')->insertOne($token);
+        return $result->getInsertedCount() > 0;
+    }
+
+    public function unsetAccessToken($access_token)
+    {
+        $result = $this->collection('access_token_table')->deleteOne(array(
+            'access_token' => $access_token
+        ));
+        return $result->getDeletedCount() > 0;
+    }
+
+    /* AuthorizationCodeInterface */
+    public function getAuthorizationCode($code)
+    {
+        $code = $this->collection('code_table')->findOne(array(
+            'authorization_code' => $code
+        ));
+        return is_null($code) ? false : $code;
+    }
+
+    public function setAuthorizationCode($code, $client_id, $user_id, $redirect_uri, $expires, $scope = null, $id_token = null)
+    {
+        // if it exists, update it.
+        if ($this->getAuthorizationCode($code)) {
+            $result = $this->collection('code_table')->updateOne(
+                array('authorization_code' => $code),
+                array('$set' => array(
+                    'client_id' => $client_id,
+                    'user_id' => $user_id,
+                    'redirect_uri' => $redirect_uri,
+                    'expires' => $expires,
+                    'scope' => $scope,
+                    'id_token' => $id_token,
+                ))
+            );
+            return $result->getMatchedCount() > 0;
+        }
+        $token = array(
+            'authorization_code' => $code,
+            'client_id' => $client_id,
+            'user_id' => $user_id,
+            'redirect_uri' => $redirect_uri,
+            'expires' => $expires,
+            'scope' => $scope,
+            'id_token' => $id_token,
+        );
+        $result = $this->collection('code_table')->insertOne($token);
+        return $result->getInsertedCount() > 0;
+    }
+
+    public function expireAuthorizationCode($code)
+    {
+        $result = $this->collection('code_table')->deleteOne(array(
+            'authorization_code' => $code
+        ));
+        return $result->getDeletedCount() > 0;
+    }
+
+    /* UserCredentialsInterface */
+    public function checkUserCredentials($username, $password)
+    {
+        if ($user = $this->getUser($username)) {
+            return $this->checkPassword($user, $password);
+        }
+        return false;
+    }
+
+    public function getUserDetails($username)
+    {
+        if ($user = $this->getUser($username)) {
+            $user['user_id'] = $user['username'];
+        }
+        return $user;
+    }
+
+    /* RefreshTokenInterface */
+    public function getRefreshToken($refresh_token)
+    {
+        $token = $this->collection('refresh_token_table')->findOne(array(
+            'refresh_token' => $refresh_token
+        ));
+        return is_null($token) ? false : $token;
+    }
+
+    public function setRefreshToken($refresh_token, $client_id, $user_id, $expires, $scope = null)
+    {
+        $token = array(
+            'refresh_token' => $refresh_token,
+            'client_id' => $client_id,
+            'user_id' => $user_id,
+            'expires' => $expires,
+            'scope' => $scope
+        );
+        $result = $this->collection('refresh_token_table')->insertOne($token);
+        return $result->getInsertedCount() > 0;
+    }
+
+    public function unsetRefreshToken($refresh_token)
+    {
+        $result = $this->collection('refresh_token_table')->deleteOne(array(
+            'refresh_token' => $refresh_token
+        ));
+        return $result->getDeletedCount() > 0;
+    }
+
+    // plaintext passwords are bad!  Override this for your application
+    protected function checkPassword($user, $password)
+    {
+        return $user['password'] == $password;
+    }
+
+    public function getUser($username)
+    {
+        $result = $this->collection('user_table')->findOne(array('username' => $username));
+        return is_null($result) ? false : $result;
+    }
+
+    public function setUser($username, $password, $firstName = null, $lastName = null)
+    {
+        if ($this->getUser($username)) {
+            $result = $this->collection('user_table')->updateOne(
+                array('username' => $username),
+                array('$set' => array(
+                    'password' => $password,
+                    'first_name' => $firstName,
+                    'last_name' => $lastName
+                ))
+            );
+
+            return $result->getMatchedCount() > 0;
+        }
+
+        $user = array(
+            'username' => $username,
+            'password' => $password,
+            'first_name' => $firstName,
+            'last_name' => $lastName
+        );
+        $result = $this->collection('user_table')->insertOne($user);
+        return $result->getInsertedCount() > 0;
+    }
+
+    public function getClientKey($client_id, $subject)
+    {
+        $result = $this->collection('jwt_table')->findOne(array(
+            'client_id' => $client_id,
+            'subject' => $subject
+        ));
+        return is_null($result) ? false : $result['key'];
+    }
+
+    public function getClientScope($client_id)
+    {
+        if (!$clientDetails = $this->getClientDetails($client_id)) {
+            return false;
+        }
+        if (isset($clientDetails['scope'])) {
+            return $clientDetails['scope'];
+        }
+        return null;
+    }
+
+    public function getJti($client_id, $subject, $audience, $expires, $jti)
+    {
+        //TODO: Needs mongodb implementation.
+        throw new \Exception('getJti() for the MongoDB driver is currently unimplemented.');
+    }
+
+    public function setJti($client_id, $subject, $audience, $expires, $jti)
+    {
+        //TODO: Needs mongodb implementation.
+        throw new \Exception('setJti() for the MongoDB driver is currently unimplemented.');
+    }
+
+    public function getPublicKey($client_id = null)
+    {
+        if ($client_id) {
+            $result = $this->collection('key_table')->findOne(array(
+                'client_id' => $client_id
+            ));
+            if ($result) {
+                return $result['public_key'];
+            }
+        }
+
+        $result = $this->collection('key_table')->findOne(array(
+            'client_id' => null
+        ));
+        return is_null($result) ? false : $result['public_key'];
+    }
+
+    public function getPrivateKey($client_id = null)
+    {
+        if ($client_id) {
+            $result = $this->collection('key_table')->findOne(array(
+                'client_id' => $client_id
+            ));
+            if ($result) {
+                return $result['private_key'];
+            }
+        }
+
+        $result = $this->collection('key_table')->findOne(array(
+            'client_id' => null
+        ));
+        return is_null($result) ? false : $result['private_key'];
+    }
+
+    public function getEncryptionAlgorithm($client_id = null)
+    {
+        if ($client_id) {
+            $result = $this->collection('key_table')->findOne(array(
+                'client_id' => $client_id
+            ));
+            if ($result) {
+                return $result['encryption_algorithm'];
+            }
+        }
+
+        $result = $this->collection('key_table')->findOne(array(
+            'client_id' => null
+        ));
+        return is_null($result) ? 'RS256' : $result['encryption_algorithm'];
+    }
+
+    // Helper function to access a MongoDB collection by `type`:
+    protected function collection($name)
+    {
+        return $this->db->{$this->config[$name]};
+    }
+}
\ No newline at end of file
diff --git a/test/lib/OAuth2/Storage/BaseTest.php b/test/lib/OAuth2/Storage/BaseTest.php
index 921d52500..f0b1274a2 100755
--- a/test/lib/OAuth2/Storage/BaseTest.php
+++ b/test/lib/OAuth2/Storage/BaseTest.php
@@ -11,6 +11,7 @@ public function provideStorage()
         $mysql = Bootstrap::getInstance()->getMysqlPdo();
         $postgres = Bootstrap::getInstance()->getPostgresPdo();
         $mongo = Bootstrap::getInstance()->getMongo();
+        $mongoDb = Bootstrap::getInstance()->getMongoDB();
         $redis = Bootstrap::getInstance()->getRedisStorage();
         $cassandra = Bootstrap::getInstance()->getCassandraStorage();
         $dynamodb = Bootstrap::getInstance()->getDynamoDbStorage();
@@ -25,6 +26,7 @@ public function provideStorage()
             array($mysql),
             array($postgres),
             array($mongo),
+            array($mongoDb),
             array($redis),
             array($cassandra),
             array($dynamodb),
diff --git a/test/lib/OAuth2/Storage/Bootstrap.php b/test/lib/OAuth2/Storage/Bootstrap.php
index 4ac9022b1..3d7bdd4e9 100755
--- a/test/lib/OAuth2/Storage/Bootstrap.php
+++ b/test/lib/OAuth2/Storage/Bootstrap.php
@@ -11,6 +11,7 @@ class Bootstrap
     private $sqlite;
     private $postgres;
     private $mongo;
+    private $mongoDb;
     private $redis;
     private $cassandra;
     private $configDir;
@@ -137,13 +138,12 @@ public function getMysqlPdo()
     public function getMongo()
     {
         if (!$this->mongo) {
-            $skipMongo = $this->getEnvVar('SKIP_MONGO_TESTS');
-            if (!$skipMongo && class_exists('MongoClient')) {
+            if (class_exists('MongoClient')) {
                 $mongo = new \MongoClient('mongodb://localhost:27017', array('connect' => false));
                 if ($this->testMongoConnection($mongo)) {
-                    $db = $mongo->oauth2_server_php;
-                    $this->removeMongoDb($db);
-                    $this->createMongoDb($db);
+                    $db = $mongo->oauth2_server_php_legacy;
+                    $this->removeMongo($db);
+                    $this->createMongo($db);
 
                     $this->mongo = new Mongo($db);
                 } else {
@@ -157,6 +157,28 @@ public function getMongo()
         return $this->mongo;
     }
 
+    public function getMongoDb()
+    {
+        if (!$this->mongoDb) {
+            if (class_exists('MongoDB\Client')) {
+                $mongoDb = new \MongoDB\Client('mongodb://localhost:27017');
+                if ($this->testMongoDBConnection($mongoDb)) {
+                    $db = $mongoDb->oauth2_server_php;
+                    $this->removeMongoDb($db);
+                    $this->createMongoDb($db);
+
+                    $this->mongoDb = new MongoDB($db);
+                } else {
+                    $this->mongoDb = new NullStorage('MongoDB', 'Unable to connect to mongo server on "localhost:27017"');
+                }
+            } else {
+                $this->mongoDb = new NullStorage('MongoDB', 'Missing MongoDB php extension. Please install mongodb.so');
+            }
+        }
+
+        return $this->mongoDb;
+    }
+
     private function testMongoConnection(\MongoClient $mongo)
     {
         try {
@@ -168,6 +190,11 @@ private function testMongoConnection(\MongoClient $mongo)
         return true;
     }
 
+    private function testMongoDBConnection(\MongoDB\Client $mongo)
+    {
+        return true;
+    }
+
     public function getCouchbase()
     {
         if (!$this->couchbase) {
@@ -442,7 +469,7 @@ private function clearCouchbase(\Couchbase $cb)
         $cb->delete('oauth_refresh_tokens-refreshtoken');
     }
 
-    private function createMongoDb(\MongoDB $db)
+    private function createMongo(\MongoDB $db)
     {
         $db->oauth_clients->insert(array(
             'client_id' => "oauth_test_client",
@@ -468,13 +495,70 @@ private function createMongoDb(\MongoDB $db)
             'email_verified' => true,
         ));
 
+        $db->oauth_keys->insert(array(
+            'client_id'   => null,
+            'public_key' => $this->getTestPublicKey(),
+            'private_key' => $this->getTestPrivateKey(),
+            'encryption_algorithm' => 'RS256'
+        ));
+
         $db->oauth_jwt->insert(array(
             'client_id' => 'oauth_test_client',
-            'key'       => $this->getTestPublicKey(),
+            'key' => $this->getTestPublicKey(),
             'subject'   => 'test_subject',
         ));
     }
 
+    public function removeMongo(\MongoDB $db)
+    {
+        $db->drop();
+    }
+
+    private function createMongoDB(\MongoDB\Database $db)
+    {
+        $db->oauth_clients->insertOne(array(
+            'client_id' => "oauth_test_client",
+            'client_secret' => "testpass",
+            'redirect_uri' => "http://example.com",
+            'grant_types' => 'implicit password'
+        ));
+
+        $db->oauth_access_tokens->insertOne(array(
+            'access_token' => "testtoken",
+            'client_id' => "Some Client"
+        ));
+
+        $db->oauth_authorization_codes->insertOne(array(
+            'authorization_code' => "testcode",
+            'client_id' => "Some Client"
+        ));
+
+        $db->oauth_users->insertOne(array(
+            'username' => 'testuser',
+            'password' => 'password',
+            'email' => 'testuser@test.com',
+            'email_verified' => true,
+        ));
+
+        $db->oauth_keys->insertOne(array(
+            'client_id'   => null,
+            'public_key' => $this->getTestPublicKey(),
+            'private_key' => $this->getTestPrivateKey(),
+            'encryption_algorithm' => 'RS256'
+        ));
+
+        $db->oauth_jwt->insertOne(array(
+            'client_id' => 'oauth_test_client',
+            'key' => $this->getTestPublicKey(),
+            'subject'   => 'test_subject',
+        ));
+    }
+
+    public function removeMongoDB(\MongoDB\Database $db)
+    {
+        $db->drop();
+    }
+
     private function createRedisDb(Redis $storage)
     {
         $storage->setClientDetails("oauth_test_client", "testpass", "http://example.com", 'implicit password');
@@ -500,11 +584,6 @@ private function createRedisDb(Redis $storage)
         $storage->setClientKey('oauth_test_client', $this->getTestPublicKey(), 'test_subject');
     }
 
-    public function removeMongoDb(\MongoDB $db)
-    {
-        $db->drop();
-    }
-
     public function getTestPublicKey()
     {
         return file_get_contents(__DIR__.'/../../../config/keys/id_rsa.pub');