diff --git a/swh/journal/replay.py b/swh/journal/replay.py
index 3321237..1b22b3b 100644
--- a/swh/journal/replay.py
+++ b/swh/journal/replay.py
@@ -1,55 +1,56 @@
 # Copyright (C) 2019 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import logging
 
 from swh.storage import HashCollision
 from swh.objstorage.objstorage import ID_HASH_ALGO
 
 
 logger = logging.getLogger(__name__)
 
 
 def process_replay_objects(all_objects, *, storage):
     for (object_type, objects) in all_objects.items():
         _insert_objects(object_type, objects, storage)
 
 
 def _insert_objects(object_type, objects, storage):
     if object_type == 'content':
         # TODO: insert 'content' in batches
         for object_ in objects:
             try:
                 storage.content_add_metadata([object_])
             except HashCollision as e:
                 logger.error('Hash collision: %s', e.args)
     elif object_type in ('directory', 'revision', 'release',
                          'snapshot', 'origin'):
         # TODO: split batches that are too large for the storage
         # to handle?
         method = getattr(storage, object_type + '_add')
         method(objects)
     elif object_type == 'origin_visit':
         storage.origin_visit_upsert([
             {
                 **obj,
                 'origin': storage.origin_add_one(obj['origin'])
             }
             for obj in objects])
     else:
-        assert False
+        logger.warning('Received a series of %s, this should not happen',
+                       object_type)
 
 
 def process_replay_objects_content(all_objects, *, src, dst):
     for (object_type, objects) in all_objects.items():
         if object_type != 'content':
             logger.warning('Received a series of %s, this should not happen',
                            object_type)
             continue
         for obj in objects:
             if obj['status'] == 'visible':
                 obj_id = obj[ID_HASH_ALGO]
                 obj = src.get(obj_id)
                 dst.add(obj, obj_id=obj_id)