diff --git a/src/caosdb/common/models.py b/src/caosdb/common/models.py
index fff96d8be7c1a60ba085a6ce21dfb70127ee3143..f7e23632ee5acb90f9849974596530166433c647 100644
--- a/src/caosdb/common/models.py
+++ b/src/caosdb/common/models.py
@@ -1606,14 +1606,6 @@ class Parent(Entity):
         return super().to_xml(xml=xml, add_properties=add_properties)
 
 
-class _EntityWrapper(object):
-    pass
-
-
-class _ConcreteProperty(_EntityWrapper):
-    pass
-
-
 class Property(Entity):
 
     """CaosDB's Property object."""