--- a/src/pyams_media/zmi/media.py	Mon Sep 11 15:33:50 2017 +0200
+++ b/src/pyams_media/zmi/media.py	Tue Sep 19 11:01:45 2017 +0200
@@ -109,7 +109,7 @@
     def applyChanges(self, data):
         media = self.getContent()
         ITransactionManager(media).get().addAfterCommitHook(check_media_conversion, kws={'media': media})
-        return True
+        return {Interface: ()}
 
 
 @view_config(name='restart-video-conversions.json', context=IVideo, request_type=IPyAMSLayer,