Index: Ringtoets/Piping/src/Ringtoets.Piping.Primitives/RingtoetsPipingSurfaceLine.cs
===================================================================
diff -u -r9ca2ce99f8b1d93fb1edde4e505b5acc5094a256 -ra940166534b3dd6e778de2e7c8e7e5241f3d3381
--- Ringtoets/Piping/src/Ringtoets.Piping.Primitives/RingtoetsPipingSurfaceLine.cs	(.../RingtoetsPipingSurfaceLine.cs)	(revision 9ca2ce99f8b1d93fb1edde4e505b5acc5094a256)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Primitives/RingtoetsPipingSurfaceLine.cs	(.../RingtoetsPipingSurfaceLine.cs)	(revision a940166534b3dd6e778de2e7c8e7e5241f3d3381)
@@ -27,6 +27,7 @@
 using Core.Common.Base;
 using Core.Common.Base.Data;
 using Core.Common.Base.Geometry;
+using Ringtoets.Common.Data;
 using Ringtoets.Piping.Primitives.Exceptions;
 using Ringtoets.Piping.Primitives.Properties;
 
@@ -35,7 +36,7 @@
     /// <summary>
     /// Definition of a surfaceline for piping.
     /// </summary>
-    public class RingtoetsPipingSurfaceLine : Observable
+    public class RingtoetsPipingSurfaceLine : Observable, IMechanismSurfaceLine
     {
         private const int numberOfDecimalPlaces = 2;
         private Point2D[] localGeometry;