diff --git a/force_bdss/tests/probe_classes/mco.py b/force_bdss/tests/probe_classes/mco.py
index bc45f2f321c21ef2af2e17c39e4cea7de8d4eaa4..89c2c2f12537dc69b256d21258133d8d3cdd7094 100644
--- a/force_bdss/tests/probe_classes/mco.py
+++ b/force_bdss/tests/probe_classes/mco.py
@@ -62,6 +62,8 @@ class ProbeMCOFactory(BaseMCOFactory):
 
     mco_class = Type(ProbeMCO)
 
+    nb_output_data_values = Int(0)
+
     def create_model(self, model_data=None):
         if model_data is None:
             model_data = {}
@@ -71,7 +73,9 @@ class ProbeMCOFactory(BaseMCOFactory):
         )
 
     def create_communicator(self):
-        return self.communicator_class(self)
+        return self.communicator_class(
+            self,
+            nb_output_data_values=self.nb_output_data_values)
 
     def create_optimizer(self):
         return self.mco_class(self)
diff --git a/force_bdss/tests/test_core_evaluation_driver.py b/force_bdss/tests/test_core_evaluation_driver.py
index 1bbd5356b0b0f673aa32a0f9d944f361f5cd9e0b..6ca2c0264b5979c5cf9b867d7dcd97e10b2f1617 100644
--- a/force_bdss/tests/test_core_evaluation_driver.py
+++ b/force_bdss/tests/test_core_evaluation_driver.py
@@ -2,10 +2,8 @@ import unittest
 
 from force_bdss.tests.probe_classes.factory_registry_plugin import \
     ProbeFactoryRegistryPlugin
-from force_bdss.tests.probe_classes.mco import (
-    ProbeMCOCommunicator, ProbeMCOFactory)
-from force_bdss.tests.probe_classes.data_source import (
-    ProbeDataSourceFactory)
+from force_bdss.tests.probe_classes.mco import ProbeMCOFactory
+from force_bdss.tests.probe_classes.data_source import ProbeDataSourceFactory
 from force_bdss.tests.probe_classes.kpi_calculator import (
     ProbeKPICalculatorFactory)
 
@@ -26,12 +24,6 @@ from force_bdss.core_evaluation_driver import CoreEvaluationDriver, \
     _bind_data_values, _compute_layer_results
 
 
-class OneValueMCOCommunicator(ProbeMCOCommunicator):
-    """A communicator that returns one single datavalue, for testing purposes.
-    """
-    nb_output_data_values = 1
-
-
 class TestCoreEvaluationDriver(unittest.TestCase):
     def setUp(self):
         self.factory_registry_plugin = ProbeFactoryRegistryPlugin()
@@ -52,7 +44,7 @@ class TestCoreEvaluationDriver(unittest.TestCase):
         mco_factories = self.factory_registry_plugin.mco_factories
         mco_factories[0] = ProbeMCOFactory(
             None,
-            communicator_class=OneValueMCOCommunicator)
+            nb_output_data_values=1)
         driver = CoreEvaluationDriver(
             application=self.mock_application)
         with self.assertRaisesRegexp(