diff --git a/app/transcript.py b/app/transcript.py
index 0b686e9..bd7e39a 100644
--- a/app/transcript.py
+++ b/app/transcript.py
@@ -26,9 +26,10 @@ def fetch_transcript(video_id: str) -> str:
         "writeautomaticsub": True,
         "subtitleslangs": ["ko", "en"],
         "subtitlesformat": "json3",
-        "format": "worst",
         "quiet": True,
         "no_warnings": True,
+        "extract_flat": False,
+        "ignore_no_formats_error": True,
     }
 
     if os.path.isfile(COOKIES_SRC):