Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanism.cs
===================================================================
diff -u -rc5f90c4f9b42d985f16f99ad8732576b9217267a -r23a37b025a5d0358c1f30fb31de41a2c284519a5
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanism.cs	(.../PipingFailureMechanism.cs)	(revision c5f90c4f9b42d985f16f99ad8732576b9217267a)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/PipingFailureMechanism.cs	(.../PipingFailureMechanism.cs)	(revision 23a37b025a5d0358c1f30fb31de41a2c284519a5)
@@ -71,7 +71,7 @@
         /// <summary>
         /// Gets all available piping calculation groups.
         /// </summary>
-        public override ICalculationGroup CalculationsGroup { get; protected set; }
+        public override CalculationGroup CalculationsGroup { get; protected set; }
 
         /// <summary>
         /// Gets the available <see cref="RingtoetsPipingSurfaceLine"/> within the scope of the piping failure mechanism.