diff --git a/src/Symfony/Component/HttpFoundation/JsonResponse.php b/src/Symfony/Component/HttpFoundation/JsonResponse.php
index ef668fdf7b..2f756e8c59 100644
--- a/src/Symfony/Component/HttpFoundation/JsonResponse.php
+++ b/src/Symfony/Component/HttpFoundation/JsonResponse.php
@@ -18,6 +18,9 @@ namespace Symfony\Component\HttpFoundation;
  */
 class JsonResponse extends Response
 {
+    protected $data;
+    protected $callback;
+
     /**
      * Constructor.
      *
@@ -28,24 +31,10 @@ class JsonResponse extends Response
      */
     public function __construct($data = array(), $status = 200, $headers = array(), $jsonp = '')
     {
-        // root should be JSON object, not array
-        if (is_array($data) && 0 === count($data)) {
-            $data = new \ArrayObject();
-        }
+        parent::__construct('', $status, $headers);
 
-        $content = json_encode($data);
-        $contentType = 'application/json';
-        if (!empty($jsonp)) {
-            $content = sprintf('%s(%s);', $jsonp, $content);
-            // Not using application/javascript for compatibility reasons with older browsers.
-            $contentType = 'text/javascript';
-        }
-
-        parent::__construct(
-            $content,
-            $status,
-            array_merge(array('Content-Type' => $contentType), $headers)
-        );
+        $this->setData($data);
+        $this->setCallback($jsonp);
     }
 
     /**
@@ -57,4 +46,56 @@ class JsonResponse extends Response
     {
         return new static($data, $status, $headers, $jsonp = '');
     }
+
+    /**
+     * Sets the JSONP callback.
+     *
+     * @param string $callback
+     *
+     * @return JsonResponse
+     */
+    public function setCallback($callback)
+    {
+        $this->callback = $callback;
+
+        return $this->update();
+    }
+
+    /**
+     * Sets the data to be sent as json.
+     *
+     * @param mixed $data
+     *
+     * @return JsonResponse
+     */
+    public function setData($data = array())
+    {
+        // root should be JSON object, not array
+        if (is_array($data) && 0 === count($data)) {
+            $data = new \ArrayObject();
+        }
+
+        $this->data = json_encode($data);
+
+        return $this->update();
+    }
+
+    /**
+     * Updates the content and headers according to the json data and callback.
+     *
+     * @return JsonResponse
+     */
+    protected function update()
+    {
+        $content = $this->data;
+        $this->headers->set('Content-Type', 'application/json', false);
+
+        if (!empty($this->callback)) {
+            $content = sprintf('%s(%s);', $this->callback, $content);
+            // Not using application/javascript for compatibility reasons with older browsers.
+            $this->headers->set('Content-Type', 'text/javascript', true);
+        }
+
+        return $this->setContent($content);
+    }
 }
diff --git a/tests/Symfony/Tests/Component/HttpFoundation/JsonResponseTest.php b/tests/Symfony/Tests/Component/HttpFoundation/JsonResponseTest.php
index 51c33e91ea..ca7687d1af 100644
--- a/tests/Symfony/Tests/Component/HttpFoundation/JsonResponseTest.php
+++ b/tests/Symfony/Tests/Component/HttpFoundation/JsonResponseTest.php
@@ -15,6 +15,8 @@ use Symfony\Component\HttpFoundation\JsonResponse;
 
 /**
  * @covers Symfony\Component\HttpFoundation\JsonResponse::__construct
+ * @covers Symfony\Component\HttpFoundation\JsonResponse::setData
+ * @covers Symfony\Component\HttpFoundation\JsonResponse::setCallback
  */
 class JsonResponseTest extends \PHPUnit_Framework_TestCase
 {
@@ -94,4 +96,12 @@ class JsonResponseTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('callback({"foo":"bar"});', $response->getContent());
         $this->assertEquals('text/javascript', $response->headers->get('Content-Type'));
     }
+
+    public function testSetCallback()
+    {
+        $response = JsonResponse::create(array('foo' => 'bar'))->setCallback('callback');
+
+        $this->assertEquals('callback({"foo":"bar"});', $response->getContent());
+        $this->assertEquals('text/javascript', $response->headers->get('Content-Type'));
+    }
 }