Index: Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Data.Test/HeightStructuresFailureMechanismTest.cs
===================================================================
diff -u -r183d1e7ed095ea4e8024068bc4ddfcf3ac6997d3 -rdd8f41ce9d9ff9fd570874721a114560c7a71013
--- Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Data.Test/HeightStructuresFailureMechanismTest.cs	(.../HeightStructuresFailureMechanismTest.cs)	(revision 183d1e7ed095ea4e8024068bc4ddfcf3ac6997d3)
+++ Ringtoets/HeightStructures/test/Ringtoets.HeightStructures.Data.Test/HeightStructuresFailureMechanismTest.cs	(.../HeightStructuresFailureMechanismTest.cs)	(revision dd8f41ce9d9ff9fd570874721a114560c7a71013)
@@ -19,6 +19,7 @@
 // Stichting Deltares and remain full property of Stichting Deltares at all times.
 // All rights reserved.
 
+using System.Collections.Generic;
 using System.Linq;
 using Core.Common.Base.Geometry;
 using NUnit.Framework;
@@ -120,7 +121,7 @@
             mocks.ReplayAll();
 
             // Call
-            var calculations = failureMechanism.Calculations.ToList();
+            List<ICalculation> calculations = failureMechanism.Calculations.ToList();
 
             // Assert
             Assert.AreEqual(2, calculations.Count);