diff --git a/lib/Newsletter/Renderer/Renderer.php b/lib/Newsletter/Renderer/Renderer.php
index 26d392646f..901e773454 100644
--- a/lib/Newsletter/Renderer/Renderer.php
+++ b/lib/Newsletter/Renderer/Renderer.php
@@ -13,8 +13,9 @@ class Renderer {
   const NEWSLETTER_TEMPLATE = 'Template.html';
   const POST_PROCESS_FILTER = 'mailpoet_rendering_post_process';
 
-  function __construct(array $newsletter, $preview = false) {
-    $this->newsletter = $newsletter;
+  function __construct($newsletter, $preview = false) {
+    // TODO: remove ternary condition, refactor to use model objects
+    $this->newsletter = (is_object($newsletter)) ? $newsletter->asArray() : $newsletter;
     $this->preview = $preview;
     $this->blocks_renderer = new Blocks\Renderer($this->newsletter, $this->preview);
     $this->columns_renderer = new Columns\Renderer();