Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/Extensions/PipingInputExtensions.cs
===================================================================
diff -u -rc4a451685003d5e96ddcc9ef043f0a9be9311839 -r98a9ab8c8767367a37ccde50f98af06d1c28ed3e
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/Extensions/PipingInputExtensions.cs	(.../PipingInputExtensions.cs)	(revision c4a451685003d5e96ddcc9ef043f0a9be9311839)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/Extensions/PipingInputExtensions.cs	(.../PipingInputExtensions.cs)	(revision 98a9ab8c8767367a37ccde50f98af06d1c28ed3e)
@@ -76,6 +76,8 @@
             catch
             {
                 input.ExitPointL = oldValue;
+                input.UpdateThicknessCoverageLayer();
+                input.UpdateThicknessAquiferLayer();
                 throw;
             }
         }
Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Extensions/PipingInputExtensionsTest.cs
===================================================================
diff -u -rc4a451685003d5e96ddcc9ef043f0a9be9311839 -r98a9ab8c8767367a37ccde50f98af06d1c28ed3e
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Extensions/PipingInputExtensionsTest.cs	(.../PipingInputExtensionsTest.cs)	(revision c4a451685003d5e96ddcc9ef043f0a9be9311839)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Extensions/PipingInputExtensionsTest.cs	(.../PipingInputExtensionsTest.cs)	(revision 98a9ab8c8767367a37ccde50f98af06d1c28ed3e)
@@ -730,20 +730,24 @@
             Assert.AreEqual(0.5, input.ThicknessAquiferLayer.Mean.Value);
         }
 
-
         [Test]
         public void SetExitPointL_ExitPointPastSurfaceLine_ThrowsArgumentOutOfRangeExceptionExitPointLNotChanged()
         {
             // Setup
-            var input = CreateInputWithAquiferAndCoverageLayer();
+            var input = CreateInputWithAquiferAndCoverageLayer(true);
+
             var exitPointBefore = input.ExitPointL;
+            var thicknessCoverageLayerBefore = input.ThicknessCoverageLayer.Mean;
+            var thicknessAquiferLayerBefore = input.ThicknessAquiferLayer.Mean;
 
             // Call
             TestDelegate test = () => input.SetExitPointL((RoundedDouble)1.1);
 
             // Assert
             Assert.Throws<ArgumentOutOfRangeException>(test);
             Assert.AreEqual(exitPointBefore, input.ExitPointL);
+            Assert.AreEqual(thicknessCoverageLayerBefore, input.ThicknessCoverageLayer.Mean);
+            Assert.AreEqual(thicknessAquiferLayerBefore, input.ThicknessAquiferLayer.Mean);
         }
 
         [Test]