diff --git a/swh/scheduler/celery_backend/config.py b/swh/scheduler/celery_backend/config.py
--- a/swh/scheduler/celery_backend/config.py
+++ b/swh/scheduler/celery_backend/config.py
@@ -91,7 +91,6 @@
     for these task classes.
 
     """
-
     for module_name in itertools.chain(
             # celery worker -I flag
             instance.app.conf['include'],
@@ -105,6 +104,9 @@
                     isinstance(obj, type)
                     and issubclass(obj, Task)
                     and obj != Task  # Don't register the abstract class itself
+                    and not name.endswith('Base')
+                    and not name.startswith('_')
+                    and obj.__module__ == module.__name__
             ):
                 class_name = '%s.%s' % (module_name, name)
                 instance.app.register_task_class(class_name, obj)