Index: Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.Data.Test/GrassCoverErosionInwardsFailureMechanismTest.cs
===================================================================
diff -u -r4936ea40e490dd8a3ed500e1c5a8f8390ff31491 -r89e5c41b732ccf30350026e8d35a01d9a180fdfc
--- Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.Data.Test/GrassCoverErosionInwardsFailureMechanismTest.cs	(.../GrassCoverErosionInwardsFailureMechanismTest.cs)	(revision 4936ea40e490dd8a3ed500e1c5a8f8390ff31491)
+++ Ringtoets/GrassCoverErosionInwards/test/Ringtoets.GrassCoverErosionInwards.Data.Test/GrassCoverErosionInwardsFailureMechanismTest.cs	(.../GrassCoverErosionInwardsFailureMechanismTest.cs)	(revision 89e5c41b732ccf30350026e8d35a01d9a180fdfc)
@@ -124,5 +124,20 @@
             Assert.IsTrue(calculations.All(c => c is GrassCoverErosionInwardsCalculation));
             mocks.VerifyAll();
         }
+
+        [Test]
+        public void Contribution_Always_UpdatesNormProbabilityInputContribution()
+        {
+            // Setup
+            var failureMechanism = new GrassCoverErosionInwardsFailureMechanism();
+            const double newContribution = 12;
+
+            // Call
+            failureMechanism.Contribution = newContribution;
+
+            // Assert
+            Assert.AreEqual(newContribution, failureMechanism.NormProbabilityInput.Contribution);
+            Assert.AreEqual(newContribution, failureMechanism.Contribution);
+        }
     }
 }
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