Index: Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.IO/StabilityPointStructuresCalculationConfiguration.cs
===================================================================
diff -u -r239e0091ca8c9878fc6d324b5a0b85179c45dbb7 -rf5b1a2d20962607a2e063bd6e5582dfaec00002d
--- Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.IO/StabilityPointStructuresCalculationConfiguration.cs	(.../StabilityPointStructuresCalculationConfiguration.cs)	(revision 239e0091ca8c9878fc6d324b5a0b85179c45dbb7)
+++ Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.IO/StabilityPointStructuresCalculationConfiguration.cs	(.../StabilityPointStructuresCalculationConfiguration.cs)	(revision f5b1a2d20962607a2e063bd6e5582dfaec00002d)
@@ -79,7 +79,7 @@
         /// <summary>
         /// Gets or sets the inflow model type of the structure.
         /// </summary>
-        public ConfigurationInflowModelType InflowModelType { get; set; }
+        public ConfigurationInflowModelType? InflowModelType { get; set; }
 
         /// <summary>
         /// Gets or sets the stochast configuration for the inside water level of the structure.