Index: Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStub.cs
===================================================================
diff -u -r06248ce95984b8cc6d10bb6fe975419e1740e93b -r1dd76ef286d22119bbba2e1bd60209c10380e12f
--- Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStub.cs	(.../AssessmentSectionAssemblyCalculatorStub.cs)	(revision 06248ce95984b8cc6d10bb6fe975419e1740e93b)
+++ Ringtoets/AssemblyTool/test/Ringtoets.AssemblyTool.KernelWrapper.TestUtil/Calculators/Assembly/AssessmentSectionAssemblyCalculatorStub.cs	(.../AssessmentSectionAssemblyCalculatorStub.cs)	(revision 1dd76ef286d22119bbba2e1bd60209c10380e12f)
@@ -114,7 +114,12 @@
 
             FailureMechanismAssemblyCategoryGroupInput = input;
 
-            return AssembleFailureMechanismsAssemblyCategoryGroupOutput ?? AssessmentSectionAssemblyCategoryGroup.D;
+            if (AssembleFailureMechanismsAssemblyCategoryGroupOutput == null)
+            {
+                AssembleFailureMechanismsAssemblyCategoryGroupOutput = AssessmentSectionAssemblyCategoryGroup.D;
+            }
+
+            return AssembleFailureMechanismsAssemblyCategoryGroupOutput.Value;
         }
 
         public AssessmentSectionAssemblyCategoryGroup AssembleAssessmentSection(AssessmentSectionAssemblyCategoryGroup failureMechanismsWithoutProbability,
@@ -128,7 +133,12 @@
             FailureMechanismsWithoutProbabilityInput = failureMechanismsWithoutProbability;
             FailureMechanismsWithProbabilityInput = failureMechanismsWithProbability;
 
-            return AssembleAssessmentSectionCategoryGroupOutput ?? AssessmentSectionAssemblyCategoryGroup.C;
+            if (AssembleAssessmentSectionCategoryGroupOutput == null)
+            {
+                AssembleAssessmentSectionCategoryGroupOutput = AssessmentSectionAssemblyCategoryGroup.C;
+            }
+
+            return AssembleAssessmentSectionCategoryGroupOutput.Value;
         }
     }
 }
\ No newline at end of file