diff --git a/livestreams.py b/livestreams.py
index 3a852d1c46b5d03556536c4caeb0dd9d84984db8..ee76e449bae79b949482a6be0db4b50a4d781f7c 100644
--- a/livestreams.py
+++ b/livestreams.py
@@ -9,7 +9,7 @@ def livestream_thumbnail():
 	livestreams = query('SELECT streams.lecture_id, streams.handle AS livehandle FROM streams WHERE streams.active')
 	lectures = query('SELECT * FROM lectures WHERE stream_job IS NOT NULL')
 	for v in genlive(livestreams)+genlive_new(lectures):
-		schedule_job('thumbnail', {'src': v['path'], 'filename': '%i.jpg'%v['lecture_id']})
+		schedule_job('thumbnail', {'src': v['path'], 'filename': 'l_%i.jpg'%v['lecture_id']})
 
 @app.route('/internal/streaming/legacy_auth', methods=['GET', 'POST'])
 @app.route('/internal/streaming/legacy_auth/<server>', methods=['GET', 'POST'])