diff --git a/youtubedownloader/youtubedownloader.py b/youtubedownloader/youtubedownloader.py
index 2fcde08..d11a626 100644
--- a/youtubedownloader/youtubedownloader.py
+++ b/youtubedownloader/youtubedownloader.py
@@ -67,11 +67,11 @@ class YouTubeDownloader(commands.Cog):
             yt = YouTube(url=url)
             filename = f"{yt.title} ({yt.video_id})"
             if audio_only:
-                yt.streams.filter(progressive=True, only_audio=True, format='m4a')
+                yt.streams.filter(progressive=True, only_audio=True, file_extension='m4a')
                 yt.streams.order_by('abr')
                 filename_format = filename + ".m4a"
             else:
-                yt.streams.filter(progressive=True, format="mp4")
+                yt.streams.filter(progressive=True, file_extension="mp4")
                 yt.streams.order_by('resolution')
                 filename_format = filename + ".mp4"
             if os.path.isfile(path + f"{os.sep}{filename_format}"):