Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingFailureMechanismView.cs
===================================================================
diff -u -rf04895089d34bddb618db8c7001c574428be10c6 -re2b40c9e08052a476113b2cb2492f60057e6e4e1
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingFailureMechanismView.cs	(.../PipingFailureMechanismView.cs)	(revision f04895089d34bddb618db8c7001c574428be10c6)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/Views/PipingFailureMechanismView.cs	(.../PipingFailureMechanismView.cs)	(revision e2b40c9e08052a476113b2cb2492f60057e6e4e1)
@@ -139,9 +139,9 @@
         {
             if (oldMapData != null)
             {
-                mapControl.Data.Remove(oldMapData);
+                mapControl.Data.Replace(oldMapData, newMapData);
             }
-            if (newMapData != null)
+            else
             {
                 mapControl.Data.Add(newMapData);
             }