diff --git a/danmaku2ass.py b/danmaku2ass.py
index ac27058..d2d1e4f 100755
--- a/danmaku2ass.py
+++ b/danmaku2ass.py
@@ -202,7 +202,7 @@ def ReadCommentsSH5V (f, fontsize):
 def ConvertTimestamp(timestamp):
     hour, minute = divmod(timestamp, 3600)
     minute, second = divmod(minute, 60)
-    centsecond = round(second*100.0)
+    centsecond = round((second-int(second))*100.0)
     return '%d:%02d:%02d.%02d' % (int(hour), int(minute), int(second), centsecond)