Index: Application/Ringtoets/src/Application.Ringtoets.Storage/Read/DuneErosion/DuneLocationOutputEntityReadExtensions.cs
===================================================================
diff -u -r649b0974fb71df7368d19682bc255618f44d49c1 -r3f76c829224b930bc043d69bffecabd17ad5019a
--- Application/Ringtoets/src/Application.Ringtoets.Storage/Read/DuneErosion/DuneLocationOutputEntityReadExtensions.cs	(.../DuneLocationOutputEntityReadExtensions.cs)	(revision 649b0974fb71df7368d19682bc255618f44d49c1)
+++ Application/Ringtoets/src/Application.Ringtoets.Storage/Read/DuneErosion/DuneLocationOutputEntityReadExtensions.cs	(.../DuneLocationOutputEntityReadExtensions.cs)	(revision 3f76c829224b930bc043d69bffecabd17ad5019a)
@@ -19,6 +19,7 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System;
 using Application.Ringtoets.Storage.DbContext;
 using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.DuneErosion.Data;
@@ -36,8 +37,14 @@
         /// </summary>
         /// <param name="entity">The <see cref="DuneLocationOutputEntity"/> to create <see cref="DuneLocationCalculationOutput"/> for.</param>
         /// <returns>A new <see cref="DuneLocationCalculationOutput"/>.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="entity"/> is <c>null</c>.</exception>
         internal static DuneLocationCalculationOutput Read(this DuneLocationOutputEntity entity)
         {
+            if (entity == null)
+            {
+                throw new ArgumentNullException(nameof(entity));
+            }
+
             return new DuneLocationCalculationOutput((CalculationConvergence) entity.CalculationConvergence, new DuneLocationCalculationOutput.ConstructionProperties
             {
                 WaterLevel = entity.WaterLevel.ToNullAsNaN(),