--- a/src/pyams_media/video.py	Tue Sep 19 11:01:45 2017 +0200
+++ b/src/pyams_media/video.py	Tue Sep 19 11:02:29 2017 +0200
@@ -135,6 +135,7 @@
                 self.thumbnail = annotations[THUMBNAIL_ANNOTATION_KEY] = image
                 locate(self.thumbnail, self.video)
                 registry.notify(ObjectAddedEvent(image, self.video))
+                transaction.commit()
         if self.thumbnail is not None:
             size_name = '{0[0]}x{0[1]}'.format(self.get_image_size())
             if thumbnail_name != size_name: