Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs
===================================================================
diff -u -r5d5d353c6b6bdda426324c591029b096621abaa4 -r16cb360eae0014270ebb6700054afdbbd565ae65
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs	(.../ClosingStructuresCalculationService.cs)	(revision 5d5d353c6b6bdda426324c591029b096621abaa4)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Service/ClosingStructuresCalculationService.cs	(.../ClosingStructuresCalculationService.cs)	(revision 16cb360eae0014270ebb6700054afdbbd565ae65)
@@ -128,7 +128,7 @@
             canceled = true;
         }
 
-        public bool Validate(StructuresCalculation<ClosingStructuresInput> calculation, IAssessmentSection assessmentSection)
+        public static bool Validate(StructuresCalculation<ClosingStructuresInput> calculation, IAssessmentSection assessmentSection)
         {
             CalculationServiceHelper.LogValidationBeginTime(calculation.Name);
             var messages = ValidateInput(calculation.InputParameters, assessmentSection);