diff --git a/Models/Promotion.php b/Models/Promotion.php
index 640fb0c..f1f0fb4 100644
--- a/Models/Promotion.php
+++ b/Models/Promotion.php
@@ -72,10 +72,10 @@ class Promotion
     /**
      * Created at.
      *
-     * @var null|\DateTime
+     * @var \DateTime
      * @since 1.0.0
      */
-    private ?\DateTime $createdAt = null;
+    private \DateTime $createdAt;
 
     /**
      * Created by.