diff --git a/livesync/indico_livesync/models/queue.py b/livesync/indico_livesync/models/queue.py
index 707bfdf..a61281e 100644
--- a/livesync/indico_livesync/models/queue.py
+++ b/livesync/indico_livesync/models/queue.py
@@ -176,7 +176,7 @@ class LiveSyncQueueEntry(db.Model):
         backref=db.backref(
             'livesync_queue_entries',
             cascade='all, delete-orphan',
-            lazy=True
+            lazy='dynamic'
         )
     )
 
@@ -186,7 +186,7 @@ class LiveSyncQueueEntry(db.Model):
         backref=db.backref(
             'livesync_queue_entries',
             cascade='all, delete-orphan',
-            lazy=True
+            lazy='dynamic'
         )
     )