diff --git a/youtube_dl/postprocessor/ffmpeg.py b/youtube_dl/postprocessor/ffmpeg.py
index 048525efc..473536dcc 100644
--- a/youtube_dl/postprocessor/ffmpeg.py
+++ b/youtube_dl/postprocessor/ffmpeg.py
@@ -520,7 +520,7 @@ def run(self, info):
 class FFmpegMergerPP(FFmpegPostProcessor):
     def run(self, info):
         filename = info['filepath']
-        args = ['-c', 'copy', '-map', '0:v:0', '-map', '1:a:0', '-shortest']
+        args = ['-c', 'copy', '-map', '0:v:0', '-map', '1:a:0']
         self._downloader.to_screen('[ffmpeg] Merging formats into "%s"' % filename)
         self.run_ffmpeg_multiple_files(info['__files_to_merge'], filename, args)
         return True, info