diff --git a/lib/Tmdb/Model/Tv/Episode.php b/lib/Tmdb/Model/Tv/Episode.php
index 9c05084d..8d274b76 100644
--- a/lib/Tmdb/Model/Tv/Episode.php
+++ b/lib/Tmdb/Model/Tv/Episode.php
@@ -151,7 +151,7 @@ public function __construct()
     }
 
     /**
-     * @return DateTime
+     * @return ?DateTime
      */
     public function getAirDate()
     {