diff --git a/sorter.py b/sorter.py
index c8c2f9e572c2b0025c1a01c8de61f3201a10af43..7d2f72c704c9f2303805a0a9a48a9804d1357f47 100644
--- a/sorter.py
+++ b/sorter.py
@@ -51,7 +51,7 @@ def schedule_thumbnail(lectureid):
 @csrf_protect
 @handle_errors('jobs_overview', 'Zu dieser Veranstaltung existieren keine Videos!', 404, IndexError)
 def add_thumbnail_job():
-	schedule_thumbnail(request.values['lectureid'])
+	schedule_thumbnail(int(request.values['lectureid']))
 	return redirect(request.values.get('ref', url_for('jobs_overview')))
 
 def insert_video(lectureid, dbfilepath, fileformatid, hash="", filesize=-1, duration=-1, sourceid=None):