diff --git a/force_bdss/mco/parameters/base_mco_parameter.py b/force_bdss/mco/parameters/base_mco_parameter.py
index de14213819f88c16c3136149a352806a4b89ecbb..cad3437312aad9434b0c3c01195dacabeeb621be 100644
--- a/force_bdss/mco/parameters/base_mco_parameter.py
+++ b/force_bdss/mco/parameters/base_mco_parameter.py
@@ -18,3 +18,7 @@ class BaseMCOParameter(HasStrictTraits):
     factory = Instance(BaseMCOParameterFactory)
     value_name = String()
     value_type = String()
+
+    def __init__(self, factory, *args, **kwargs):
+        self.factory = factory
+        super(BaseMCOParameter, self).__init__(*args, **kwargs)