Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil.Test/Calculators/Categories/AssemblyCategoriesCalculatorStubTest.cs
===================================================================
diff -u -r4160a30705d657946461b76a5c443119cb78d437 -r20d123c40d0d306e64a2d7881d428e36bde9dc2d
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil.Test/Calculators/Categories/AssemblyCategoriesCalculatorStubTest.cs	(.../AssemblyCategoriesCalculatorStubTest.cs)	(revision 4160a30705d657946461b76a5c443119cb78d437)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil.Test/Calculators/Categories/AssemblyCategoriesCalculatorStubTest.cs	(.../AssemblyCategoriesCalculatorStubTest.cs)	(revision 20d123c40d0d306e64a2d7881d428e36bde9dc2d)
@@ -21,6 +21,7 @@
 
 using System.Collections.Generic;
 using NUnit.Framework;
+using Ringtoets.AssemblyTool.Data.Input;
 using Ringtoets.AssemblyTool.Data.Output;
 using Ringtoets.AssemblyTool.KernelWrapper.Calculators.Categories;
 using Ringtoets.AssemblyTool.KernelWrapper.TestUtil.Calculators.Categories;
@@ -54,5 +55,19 @@
             // Assert
             CollectionAssert.IsEmpty(result);
         }
+
+        [Test]
+        public void CalculateAssessmentSectionCategories_Always_SetsInput()
+        {
+            // Setup
+            var input = new AssemblyCategoriesCalculatorInput(0, 0);
+            var calculator = new AssemblyCategoriesCalculatorStub();
+
+            // Call
+            calculator.CalculateAssessmentSectionCategories(input);
+
+            // Assert
+            Assert.AreSame(input, calculator.Input);
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Categories/AssemblyCategoriesCalculatorStub.cs
===================================================================
diff -u -r4160a30705d657946461b76a5c443119cb78d437 -r20d123c40d0d306e64a2d7881d428e36bde9dc2d
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Categories/AssemblyCategoriesCalculatorStub.cs	(.../AssemblyCategoriesCalculatorStub.cs)	(revision 4160a30705d657946461b76a5c443119cb78d437)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Categories/AssemblyCategoriesCalculatorStub.cs	(.../AssemblyCategoriesCalculatorStub.cs)	(revision 20d123c40d0d306e64a2d7881d428e36bde9dc2d)
@@ -34,7 +34,7 @@
         /// <summary>
         /// Gets or sets the assembly categories calculator input.
         /// </summary>
-        public AssemblyCategoriesCalculatorInput Input { get; set; }
+        public AssemblyCategoriesCalculatorInput Input { get; private set; }
 
         /// <summary>
         /// Gets the output of the <see cref="CalculateAssessmentSectionCategories"/> calculation.
@@ -44,6 +44,8 @@
         public IEnumerable<AssessmentSectionAssemblyCategoryResult> CalculateAssessmentSectionCategories(
             AssemblyCategoriesCalculatorInput input)
         {
+            Input = input;
+
             return AssessmentSectionCategoriesOutput
                    ?? (AssessmentSectionCategoriesOutput = new AssessmentSectionAssemblyCategoryResult[0]);
         }