diff --git a/src/Acquia/Rest/Collection.php b/src/Acquia/Rest/Collection.php
index 536410b..efe169d 100644
--- a/src/Acquia/Rest/Collection.php
+++ b/src/Acquia/Rest/Collection.php
@@ -2,8 +2,6 @@
 
 namespace Acquia\Rest;
 
-use Guzzle\Http\Message\RequestInterface;
-
 class Collection extends \ArrayObject
 {
     /**
@@ -29,11 +27,19 @@ class Collection extends \ArrayObject
     protected $collectionProperty;
 
     /**
-     * @param \Guzzle\Http\Message\RequestInterface $request
+     * @param \Guzzle\Http\Message\RequestInterface|\GuzzleHttp\Message\Response $dataSource
      */
-    public function __construct(RequestInterface $request)
+    public function __construct($dataSource)
     {
-        $this->response = $request->send();
+        if (is_a($dataSource, '\Guzzle\Http\Message\RequestInterface')) {
+            $this->response = $dataSource->send();
+        } elseif (is_a($dataSource, '\GuzzleHttp\Message\Response')) {
+            $this->response = $dataSource;
+        } else {
+            throw new \InvalidArgumentException(
+                sprintf("%s can't be constructed using data from %s.", get_class($this), get_class($dataSource))
+            );
+        }
         parent::__construct($this->response->json());
     }
 
diff --git a/src/Acquia/Rest/Element.php b/src/Acquia/Rest/Element.php
index d72d48e..1e960bc 100644
--- a/src/Acquia/Rest/Element.php
+++ b/src/Acquia/Rest/Element.php
@@ -2,8 +2,6 @@
 
 namespace Acquia\Rest;
 
-use Guzzle\Http\Message\Request;
-
 class Element extends \ArrayObject
 {
     /**
@@ -12,16 +10,18 @@ class Element extends \ArrayObject
     protected $idColumn = 'name';
 
     /**
-     * @param string|array|\Guzzle\Http\Message\Request $array
+     * @param string|array|\Guzzle\Http\Message\RequestInterface|\GuzzleHttp\Message\Response $dataSource
      */
-    public function __construct($data)
+    public function __construct($dataSource)
     {
-        if ($data instanceof Request) {
-            $array = $data->send()->json();
-        } elseif (is_string($data)) {
-            $array = array($this->idColumn => $data);
+        if (is_a($dataSource, '\Guzzle\Http\Message\RequestInterface')) {
+            $array = $dataSource->send()->json();
+        } elseif (is_a($dataSource, '\GuzzleHttp\Message\Response')) {
+            $array = $dataSource->json();
+        } elseif (is_string($dataSource)) {
+            $array = array($this->idColumn => $dataSource);
         } else {
-            $array = (array) $data;
+            $array = (array) $dataSource;
         }
         parent::__construct($array);
     }
diff --git a/src/Acquia/Rest/composer.json b/src/Acquia/Rest/composer.json
index 5e38b58..aadb08e 100644
--- a/src/Acquia/Rest/composer.json
+++ b/src/Acquia/Rest/composer.json
@@ -14,9 +14,12 @@
     "require": {
         "php": ">=5.3.0",
         "acquia/acquia-sdk-php-json": "self.version",
-        "guzzle/service": "~3.0",
         "symfony/filesystem": "~2.0"
     },
+    "suggest": {
+        "guzzlehttp/guzzle": "The current version of Guzzle may be useful with Collection and Element classes.",
+        "guzzle/service": "This older (deprecated) version of Guzzle may be useful with Collection and Element classes."
+    },
     "autoload": {
         "psr-0": {
             "Acquia\\Rest": ""