diff --git a/swh/scheduler/backend.py b/swh/scheduler/backend.py
--- a/swh/scheduler/backend.py
+++ b/swh/scheduler/backend.py
@@ -173,6 +173,9 @@
               where id in %s
         """
 
+        if not lister_ids:
+            return []
+
         cur.execute(query, (tuple(lister_ids),))
 
         return [Lister(**row) for row in cur]