Index: Ringtoets/Revetment/src/Ringtoets.Revetment.Service/WaveConditionsCalculationServiceBase.cs
===================================================================
diff -u -ra81fb4d326ce43c7f94d464aba21611a4582cd22 -r6836b668105d755b71835b56716b3254815b5c92
--- Ringtoets/Revetment/src/Ringtoets.Revetment.Service/WaveConditionsCalculationServiceBase.cs	(.../WaveConditionsCalculationServiceBase.cs)	(revision a81fb4d326ce43c7f94d464aba21611a4582cd22)
+++ Ringtoets/Revetment/src/Ringtoets.Revetment.Service/WaveConditionsCalculationServiceBase.cs	(.../WaveConditionsCalculationServiceBase.cs)	(revision 6836b668105d755b71835b56716b3254815b5c92)
@@ -405,7 +405,7 @@
             {
                 messages.Add(Resources.WaveConditionsCalculationService_ValidateInput_No_HydraulicBoundaryLocation_selected);
             }
-            else if (double.IsNaN(input.HydraulicBoundaryLocation.DesignWaterLevel))
+            else if (double.IsNaN(normativeAssessmentLevel))
             {
                 messages.Add(string.Format(CultureInfo.CurrentCulture,
                                            Resources.WaveConditionsCalculationService_ValidateInput_No_0_DesignWaterLevel_calculated,