diff --git a/force_bdss/mco/base_mco_factory.py b/force_bdss/mco/base_mco_factory.py
index f7fff0922a3ddd5dff13bfa6bd137627e8434f9e..c8236553961461ff3e502e0fab73a5abccf10644 100644
--- a/force_bdss/mco/base_mco_factory.py
+++ b/force_bdss/mco/base_mco_factory.py
@@ -92,13 +92,6 @@ class BaseMCOFactory(HasStrictTraits):
         BaseMCO
             The optimizer
         """
-        if self.optimizer_class is None:
-            msg = ("optimizer_class cannot be None in {}. Either define "
-                   "optimizer_class or reimplement create_optimizer on "
-                   "your factory class.".format(self.__class__.__name__))
-            log.error(msg)
-            raise RuntimeError(msg)
-
         return self.optimizer_class(self)
 
     def create_model(self, model_data=None):
@@ -122,13 +115,6 @@ class BaseMCOFactory(HasStrictTraits):
         if model_data is None:
             model_data = {}
 
-        if self.model_class is None:
-            msg = ("model_class cannot be None in {}. Either define "
-                   "model_class or reimplement create_model on your "
-                   "factory class.".format(self.__class__.__name__))
-            log.error(msg)
-            raise RuntimeError(msg)
-
         return self.model_class(self, **model_data)
 
     def create_communicator(self):
@@ -140,13 +126,6 @@ class BaseMCOFactory(HasStrictTraits):
         BaseMCOCommunicator
             An instance of the communicator
         """
-        if self.communicator_class is None:
-            msg = ("communicator_class cannot be None in {}. Either define "
-                   "communicator_class or reimplement create_communicator on "
-                   "your factory class.".format(self.__class__.__name__))
-            log.error(msg)
-            raise RuntimeError(msg)
-
         return self.communicator_class(self)
 
     def parameter_factories(self):
diff --git a/force_bdss/ui_hooks/base_ui_hooks_factory.py b/force_bdss/ui_hooks/base_ui_hooks_factory.py
index af62ffb8b27d23ba0af90a1eab1982ab9e529221..2aaa66c5b067cb47c20a68b5aa1caa9ff57d594a 100644
--- a/force_bdss/ui_hooks/base_ui_hooks_factory.py
+++ b/force_bdss/ui_hooks/base_ui_hooks_factory.py
@@ -79,12 +79,4 @@ class BaseUIHooksFactory(HasStrictTraits):
         -------
         BaseUIHooksManager
         """
-        if self.ui_hooks_manager_class is None:
-            msg = ("ui_hooks_manager_class cannot be None in {}. Either "
-                   "define ui_hooks_manager_class or reimplement "
-                   "create_ui_hooks_manager on "
-                   "your factory class.".format(self.__class__.__name__))
-            log.error(msg)
-            raise RuntimeError(msg)
-
         return self.ui_hooks_manager_class(self)