diff --git a/workflow/video.py b/workflow/video.py
index bf6af83..fd0e2e5 100644
--- a/workflow/video.py
+++ b/workflow/video.py
@@ -214,7 +214,7 @@ def quick_split_video(file):
         split_process = subprocess.Popen([
             FFMPEG_EXEC, *_common_ffmpeg_setting(),
             "-ss", str(current_sec),
-            "-i", file, "-c", "copy", "-f", "mp4",
+            "-i", file, "-c:v", "copy", "-c:a", "aac", "-f", "mp4",
             "-t", str(VIDEO_CLIP_EACH_SEC + VIDEO_CLIP_OVERFLOW_SEC),
             "-fflags", "+genpts", "-shortest", "-movflags", "faststart",
             os.path.join(VIDEO_OUTPUT_DIR, "{}.mp4".format(current_dt))
@@ -237,7 +237,7 @@ def _common_ffmpeg_setting():
 
 def _common_ffmpeg_params():
     return (
-        "-f", "mp4", "-b:v", VIDEO_BITRATE, "-c:a", "copy",
+        "-f", "mp4", "-b:v", VIDEO_BITRATE, "-c:a", "aac",
         "-preset:v", "fast", "-profile:v", "main", "-avoid_negative_ts", "1",
         "-qmin", "18", "-qmax", "38", "-crf", str(VIDEO_CRF), "-g:v", str(VIDEO_GOP),
         "-fflags", "+genpts", "-shortest"