diff --git a/tv_audio_encoder.py b/tv_audio_encoder.py
index 5539b68..9693caf 100644
--- a/tv_audio_encoder.py
+++ b/tv_audio_encoder.py
@@ -201,7 +201,16 @@ def main(no_downmix=False):
             audio_tracks_to_remux = []
             audio_streams = [s for s in ffprobe_info.get("streams", []) if s.get("codec_type") == "audio"]
 
+            # Build mkvmerge track mapping by track ID
+            mkv_audio_tracks = {t["id"]: t for t in mkv_info.get("tracks", []) if t.get("type") == "audio"}
+
+            # Build mediainfo track mapping by StreamOrder
+            media_tracks_data = media_info.get("media", {}).get("track", [])
+            mediainfo_audio_tracks = {int(t.get("StreamOrder", -1)): t for t in media_tracks_data if t.get("@type") == "Audio"}
+
             for stream in audio_streams:
+                # Extract these values once per stream for clarity
+                stream_index = stream["index"]
                 stream_index = stream["index"]
                 codec = stream.get("codec_name")
                 channels = stream.get("channels", 2)
@@ -226,6 +235,7 @@ def main(no_downmix=False):
                     # Convert any codec that is not in REMUX_CODECS
                     opus_file = convert_audio_track(
                         stream_index, channels, language, audio_temp_dir, str(input_file_abs), not no_downmix
+                        stream_index, channels, language, audio_temp_dir, str(input_file_abs), not no_downmix
                     )
                     processed_audio_files.append({
                         "Path": opus_file,
@@ -239,6 +249,7 @@ def main(no_downmix=False):
             # Final mux
             print("Assembling final file with mkvmerge...")
             mkvmerge_args = ["mkvmerge", "-o", str(intermediate_output_file), str(created_encoded_video_path)]
+
             for file_info in processed_audio_files:
                 sync_switch = ["--sync", f"0:{file_info['Delay']}"] if file_info["Delay"] else []
                 mkvmerge_args += [
@@ -247,6 +258,7 @@ def main(no_downmix=False):
                 ] + sync_switch + [str(file_info["Path"])]
 
             source_copy_args = ["--no-video"]
+
             if audio_tracks_to_remux:
                 source_copy_args += ["--audio-tracks", ",".join(audio_tracks_to_remux)]
             else: