diff --git a/app/Services/EpisodeService.php b/app/Services/EpisodeService.php
index 09d9aa2..c0b3e73 100644
--- a/app/Services/EpisodeService.php
+++ b/app/Services/EpisodeService.php
@@ -34,8 +34,8 @@ class EpisodeService
         Request $request, 
         Hentai $hentai,
         int $episodeNumber,
-        Studios $studio = null,
-        Episode $referenceEpisode = null
+        ?Studios $studio = null,
+        ?Episode $referenceEpisode = null
     ): Episode
     {
         $episode = new Episode();