Index: Ringtoets/Common/src/Ringtoets.Common.Service/DesignWaterLevelCalculationActivity.cs
===================================================================
diff -u -r8aea6e032ff8aeb4a4f1b85210fd0e2fbbce3a4a -rc78a5b1d66fba1148ab5880357ce3c20a042c9ed
--- Ringtoets/Common/src/Ringtoets.Common.Service/DesignWaterLevelCalculationActivity.cs	(.../DesignWaterLevelCalculationActivity.cs)	(revision 8aea6e032ff8aeb4a4f1b85210fd0e2fbbce3a4a)
+++ Ringtoets/Common/src/Ringtoets.Common.Service/DesignWaterLevelCalculationActivity.cs	(.../DesignWaterLevelCalculationActivity.cs)	(revision c78a5b1d66fba1148ab5880357ce3c20a042c9ed)
@@ -84,10 +84,10 @@
                 return;
             }
 
-            PerformRun(() => DesignWaterLevelCalculationService.Validate(
+            PerformRun(() => DesignWaterLevelCalculationService.Instance.Validate(
                 messageProvider.GetCalculationName(hydraulicBoundaryLocation.Name), hydraulicBoundaryDatabaseFilePath),
                        () => hydraulicBoundaryLocation.DesignWaterLevel = (RoundedDouble) double.NaN,
-                       () => DesignWaterLevelCalculationService.Calculate(
+                       () => DesignWaterLevelCalculationService.Instance.Calculate(
                            messageProvider, hydraulicBoundaryLocation, hydraulicBoundaryDatabaseFilePath,
                            ringId, norm));
         }