Index: Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Services/HydraRingConfigurationService.cs
===================================================================
diff -u -rf8c28b3b04cdabb62ea37772efcb1f4ebbbf2b9e -r0320ab3a413cb6a55e3f615d8c62706a48121588
--- Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Services/HydraRingConfigurationService.cs	(.../HydraRingConfigurationService.cs)	(revision f8c28b3b04cdabb62ea37772efcb1f4ebbbf2b9e)
+++ Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Services/HydraRingConfigurationService.cs	(.../HydraRingConfigurationService.cs)	(revision 0320ab3a413cb6a55e3f615d8c62706a48121588)
@@ -64,7 +64,7 @@
         private const double defaultHydraRingValue = 0.0;
 
         private readonly double? defaultHydraRingNullValue = null;
-        private readonly IList<HydraRingCalculationInput> hydraRingInputs = new List<HydraRingCalculationInput>();
+        private readonly List<HydraRingCalculationInput> hydraRingInputs = new List<HydraRingCalculationInput>();
         private readonly FailureMechanismDefaultsProvider failureMechanismDefaultsProvider = new FailureMechanismDefaultsProvider();
         private readonly VariableDefaultsProvider variableDefaultsProvider = new VariableDefaultsProvider();