diff --git a/src/caosadvancedtools/cfood.py b/src/caosadvancedtools/cfood.py
index d43dc8f943545d618bfb447423654012fc547d32..661a0911fe625fc452e4d4974befa40b7a00a4a8 100644
--- a/src/caosadvancedtools/cfood.py
+++ b/src/caosadvancedtools/cfood.py
@@ -212,7 +212,7 @@ class AbstractCFood(object):
 
 
 def assure_object_is_in_list(obj, containing_object, property_name,
-                             to_be_updated, verbosity=INFO):
+                             to_be_updated, datatype=None, verbosity=INFO):
     """
     Checks whether `obj` is one of the values in the list property
     `property_name` of the supplied entity  containing_object`.
@@ -228,8 +228,10 @@ def assure_object_is_in_list(obj, containing_object, property_name,
     """
 
     if containing_object.get_property(property_name) is None:
+        if datatype is None:
+            datatype = db.LIST(property_name)
         containing_object.add_property(property_name, value=[],
-                                       datatype=db.LIST(property_name))
+                                       datatype=datatype)
     current_list = containing_object.get_property(property_name).value
 
     if not isinstance(current_list, list):