diff --git a/README.md b/README.md
index cdbfbb5..f8c7d46 100644
--- a/README.md
+++ b/README.md
@@ -31,9 +31,20 @@ find adapters to use. For more information about virtual packages please refer t
 [Httplug](http://docs.httplug.io/en/latest/virtual-package/). Example:
 
 ```bash
-php composer.phar require php-http/guzzle6-adapter:dev-master
+php composer.phar require php-http/guzzle6-adapter:^1.0
 ```
 
+When creating a new `Mailgun` object you must provide an instance of the `HttpClient`.
+
+```php
+$client = new \Http\Adapter\Guzzle6\Client();
+$mailgun = new \Mailgun\Mailgun('api_key', null, null, true, $client);
+```
+
+You could also rely on the [auto discovery feature of Httplug](http://docs.php-http.org/en/latest/discovery.html). This 
+means that you need to install `puli/composer-plugin` and put a puli.phar in your project root.  
+
+
 **For shared hosts without SSH access, check out our [Shared Host Instructions](SharedHostInstall.md).**
 
 **Rather just download the files? [Library Download](https://9f67cbbd1116d8afb399-7760483f5d1e5f28c2d253278a2a5045.ssl.cf2.rackcdn.com/mailgun-php-1.7.2.zip).**
diff --git a/composer.json b/composer.json
index 83ccde4..8c6fccc 100644
--- a/composer.json
+++ b/composer.json
@@ -4,13 +4,13 @@
     "require": {
         "php": ">=5.4.0",
         "guzzlehttp/psr7": "~1.2",
-        "php-http/client-implementation": "1.0",
-        "php-http/discovery": "^0.4"
+        "php-http/httplug": "^1.0",
+        "php-http/client-implementation": "^1.0",
+        "php-http/discovery": "^0.8"
     },
     "require-dev": {
         "phpunit/phpunit": "~4.6",
-        "php-http/guzzle5-adapter": "dev-master",
-        "php-http/httplug": "v1.0.0-beta"
+        "php-http/guzzle6-adapter": "^1.0"
     },
     "autoload": {
         "psr-0": {
diff --git a/src/Mailgun/Connection/RestClient.php b/src/Mailgun/Connection/RestClient.php
index d86d709..e35f9da 100644
--- a/src/Mailgun/Connection/RestClient.php
+++ b/src/Mailgun/Connection/RestClient.php
@@ -64,8 +64,6 @@ class RestClient
      */
     protected function send($method, $uri, $body = null, $files = [], array $headers = [])
     {
-        $client = $this->getHttpClient();
-
         $headers['User-Agent'] = Api::SDK_USER_AGENT.'/'.Api::SDK_VERSION;
         $headers['Authorization'] = 'Basic '.base64_encode(sprintf('%s:%s', Api::API_USER, $this->apiKey));
 
@@ -75,7 +73,7 @@ class RestClient
         }
 
         $request = new Request($method, $this->apiEndpoint.$uri, $headers, $body);
-        $response = $client->sendRequest($request);
+        $response = $this->getHttpClient()->sendRequest($request);
 
         return $this->responseHandler($response);
     }
diff --git a/src/Mailgun/Mailgun.php b/src/Mailgun/Mailgun.php
index cee46db..2b8ebf8 100644
--- a/src/Mailgun/Mailgun.php
+++ b/src/Mailgun/Mailgun.php
@@ -37,11 +37,19 @@ class Mailgun{
      */
     public function __construct(
         $apiKey = null,
-        $apiEndpoint = "api.mailgun.net",
-        $apiVersion = "v3",
+        $apiEndpoint = null,
+        $apiVersion = null,
         $ssl = true,
         HttpClient $httpClient = null
     ) {
+        if (empty($apiEndpoint)) {
+            $apiEndpoint = "api.mailgun.net";
+        }
+
+        if (empty($apiVersion)) {
+            $apiVersion = "v3";
+        }
+
         $this->apiKey = $apiKey;
         $this->restClient = new RestClient($apiKey, $apiEndpoint, $apiVersion, $ssl, $httpClient);
     }