From 484ea99c41402b512e11dc1219a25464ca150350 Mon Sep 17 00:00:00 2001
From: Roman Saldygashev <groundflyer@users.noreply.github.com>
Date: Fri, 10 Mar 2017 19:45:56 +0600
Subject: [PATCH] add mask duration (fix #354) (#355)

---
 moviepy/video/compositing/transitions.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/moviepy/video/compositing/transitions.py b/moviepy/video/compositing/transitions.py
index d7fad86d3..920f4df8e 100644
--- a/moviepy/video/compositing/transitions.py
+++ b/moviepy/video/compositing/transitions.py
@@ -25,6 +25,7 @@ def crossfadeout(clip, duration):
     """ Makes the clip disappear progressively, over ``duration`` seconds.
     Only works when the clip is included in a CompositeVideoClip.
     """
+    clip.mask.duration = clip.duration
     newclip = clip.copy()
     newclip.mask = clip.mask.fx(fadeout, duration)
     return newclip