diff --git a/src/Core/Mailer/Mailer.php b/src/Core/Mailer/Mailer.php
index e6dc8b6e..117714f5 100644
--- a/src/Core/Mailer/Mailer.php
+++ b/src/Core/Mailer/Mailer.php
@@ -19,7 +19,7 @@
  * @see  MailAttachment
  *
  * @method  static  MailMessage             createMessage($subject = null, $content = null, $html = true)
- * @method  static  boolean                 send(MailMessage $message)
+ * @method  static  boolean|callable        send($message)
  * @method  static  MailerManager           setMessageClass($messageClass)
  * @method  static  MailerAdapterInterface  getAdapter()
  * @method  static  MailerManager           setAdapter(MailerAdapterInterface $adapter)
diff --git a/src/Core/Mailer/MailerManager.php b/src/Core/Mailer/MailerManager.php
index 9acf23d5..45fc6510 100644
--- a/src/Core/Mailer/MailerManager.php
+++ b/src/Core/Mailer/MailerManager.php
@@ -82,11 +82,13 @@ public function send($message)
 	{
 		if (is_callable($message))
 		{
-			$message = $message($this->createMessage(), $this);
+			$msgObject = $this->createMessage();
+
+			$message = $message($msgObject, $this);
 
 			if (!$message instanceof MailMessage)
 			{
-				throw new \UnexpectedValueException(sprintf('Please return %s from your callback. ', MailMessage::class));
+				$message = $msgObject;
 			}
 		}
 
diff --git a/src/Core/View/Helper/Set/HelperSet.php b/src/Core/View/Helper/Set/HelperSet.php
index 901d3d4d..8103d455 100644
--- a/src/Core/View/Helper/Set/HelperSet.php
+++ b/src/Core/View/Helper/Set/HelperSet.php
@@ -11,7 +11,6 @@
 use Windwalker\Core\Mvc\MvcHelper;
 use Windwalker\Core\View\AbstractView;
 use Windwalker\Core\View\Helper\AbstractHelper;
-use Windwalker\Core\View\PhpHtmlView;
 
 /**
  * Class HelperSet
diff --git a/src/Core/Widget/Widget.php b/src/Core/Widget/Widget.php
index 8de7a51c..afc9dded 100644
--- a/src/Core/Widget/Widget.php
+++ b/src/Core/Widget/Widget.php
@@ -14,6 +14,7 @@
 use Windwalker\Core\Package\PackageHelper;
 use Windwalker\Core\Renderer\RendererHelper;
 use Windwalker\Core\Utilities\Classes\ArrayAccessTrait;
+use Windwalker\Data\DataInterface;
 use Windwalker\Utilities\Queue\PriorityQueue;
 use Windwalker\Data\Data;
 use Windwalker\Renderer\PhpRenderer;
@@ -151,11 +152,11 @@ public function render($data = array())
 	/**
 	 * prepareData
 	 *
-	 * @param  \Windwalker\Data\Data  $data
+	 * @param  DataInterface  $data
 	 *
 	 * @return  void
 	 */
-	protected function prepareData($data)
+	protected function prepareData(DataInterface $data)
 	{
 	}
 
@@ -210,11 +211,11 @@ public function setRenderer(RendererInterface $renderer)
 	/**
 	 * prepareGlobals
 	 *
-	 * @param Data $data
+	 * @param DataInterface $data
 	 *
 	 * @return  static
 	 */
-	protected function prepareGlobals(Data $data)
+	protected function prepareGlobals(DataInterface $data)
 	{
 		$data->layout = $this->layout;
 		$data->renderer = get_class($this->renderer);