Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingFailureMechanismTest.cs
===================================================================
diff -u -rbb0aeecc47206f5089ab04ca6c3575a1de8c206f -r62d6426f4dc874b8e74a0c3ebe4c3491fa207af1
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingFailureMechanismTest.cs	(.../PipingFailureMechanismTest.cs)	(revision bb0aeecc47206f5089ab04ca6c3575a1de8c206f)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingFailureMechanismTest.cs	(.../PipingFailureMechanismTest.cs)	(revision 62d6426f4dc874b8e74a0c3ebe4c3491fa207af1)
@@ -55,9 +55,11 @@
             Assert.IsInstanceOf<GeneralPipingInput>(piping.GeneralInput);
             CollectionAssert.IsEmpty(piping.Sections);
             CollectionAssert.IsEmpty(piping.SurfaceLines);
-            Assert.IsInstanceOf<List<RingtoetsPipingSurfaceLine>>(piping.SurfaceLines);
+            Assert.IsInstanceOf<IList<RingtoetsPipingSurfaceLine>>(piping.SurfaceLines);
+            Assert.IsInstanceOf<IObservable>(piping.SurfaceLines);
             CollectionAssert.IsEmpty(piping.StochasticSoilModels);
-            Assert.IsInstanceOf<ObservableList<StochasticSoilModel>>(piping.StochasticSoilModels);
+            Assert.IsInstanceOf<IList<StochasticSoilModel>>(piping.StochasticSoilModels);
+            Assert.IsInstanceOf<IObservable>(piping.StochasticSoilModels);
             Assert.AreEqual("Berekeningen", piping.CalculationsGroup.Name);
             Assert.IsEmpty(piping.CalculationsGroup.Children);
         }