diff --git a/Models/NewsArticle.php b/Models/NewsArticle.php
index 52f456b..c5e2191 100755
--- a/Models/NewsArticle.php
+++ b/Models/NewsArticle.php
@@ -228,11 +228,11 @@ class NewsArticle implements \JsonSerializable, ArrayableInterface
     /**
      * Get date of creation
      *
-     * @return \DateTime
+     * @return \DateTimeImmutable
      *
      * @since 1.0.0
      */
-    public function getCreatedAt() : \DateTimeInterface
+    public function getCreatedAt() : \DateTimeImmutable
     {
         return $this->createdAt;
     }