diff --git a/src/ytdl_sub/plugins/file_convert.py b/src/ytdl_sub/plugins/file_convert.py
index 8d2e1cd0..6dbc6031 100644
--- a/src/ytdl_sub/plugins/file_convert.py
+++ b/src/ytdl_sub/plugins/file_convert.py
@@ -131,6 +131,7 @@ class FileConvertPlugin(Plugin[FileConvertOptions]):
         """
         if self.plugin_options.convert_with == "yt-dlp":
             return {
+                "merge_output_format": self.plugin_options.convert_to,
                 "postprocessors": [
                     {
                         "key": "FFmpegVideoRemuxer",