diff --git a/danmaku2ass.py b/danmaku2ass.py
index 6e5a249..6ae8ded 100755
--- a/danmaku2ass.py
+++ b/danmaku2ass.py
@@ -697,7 +697,7 @@ def Danmaku2ASS(input_files, output_file, stage_width, stage_height, reserve_bla
             fo = sys.stdout
         ProcessComments(comments, fo, stage_width, stage_height, reserve_blank, font_face, font_size, text_opacity, comment_duration, is_reduce_comments, progress_callback)
     finally:
-        if output_file and fo:
+        if output_file and fo != output_file:
             fo.close()