Index: Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Service.Test/HeightStructuresCalculationActivityTest.cs
===================================================================
diff -u -r76948e8765899b35776102ecd211d3d7575a9e4d -r57cf41dc262bf62fdf1dddc550884a2f79163d4e
--- Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Service.Test/HeightStructuresCalculationActivityTest.cs	(.../HeightStructuresCalculationActivityTest.cs)	(revision 76948e8765899b35776102ecd211d3d7575a9e4d)
+++ Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Service.Test/HeightStructuresCalculationActivityTest.cs	(.../HeightStructuresCalculationActivityTest.cs)	(revision 57cf41dc262bf62fdf1dddc550884a2f79163d4e)
@@ -26,6 +26,7 @@
 using Ringtoets.Common.Data.AssessmentSection;
 using Ringtoets.Common.Data.Structures;
 using Ringtoets.HeightStructures.Data;
+using Ringtoets.HydraRing.Calculation.Activities;
 
 namespace Ringtoets.HeightStructures.Service.Test
 {
@@ -47,7 +48,7 @@
             var activity = new HeightStructuresCalculationActivity(calculation, "", failureMechanism, assessmentSection);
 
             // Assert
-            Assert.IsInstanceOf<Activity>(activity);
+            Assert.IsInstanceOf<CalculatableActivity>(activity);
             Assert.AreEqual($"Uitvoeren van berekening '{calculation.Name}'", activity.Description);
             Assert.IsNull(activity.ProgressText);
             Assert.AreEqual(ActivityState.None, activity.State);