Index: Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Views/PipingChartDataFactoryTest.cs
===================================================================
diff -u -r78053965aab36c2c21e2706e73d84a9dc2cd5f3a -r166f0d43e8e9d8820a7b95503ed2196d0fc54741
--- Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Views/PipingChartDataFactoryTest.cs	(.../PipingChartDataFactoryTest.cs)	(revision 78053965aab36c2c21e2706e73d84a9dc2cd5f3a)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Forms.Test/Views/PipingChartDataFactoryTest.cs	(.../PipingChartDataFactoryTest.cs)	(revision 166f0d43e8e9d8820a7b95503ed2196d0fc54741)
@@ -168,11 +168,32 @@
             Assert.AreEqual("soilProfile", paramName);
         }
 
+        [TestCase(-1)]
+        [TestCase(2)]
+        [TestCase(3)]
+        public void CreateSoilLayerChartData_InvalidSoilLayerIndex_ThrowsArgumentOutOfRangeException(int soilLayerIndex)
+        {
+            // Setup
+            var layers = new[]
+            {
+                new PipingSoilLayer(0),
+                new PipingSoilLayer(1)
+            };
+            var profile = new PipingSoilProfile("name", -1.0, layers, SoilProfileType.SoilProfile1D, 0);
+
+            // Call
+            TestDelegate test = () => PipingChartDataFactory.CreateSoilLayerChartData(soilLayerIndex, profile);
+
+            // Assert
+            var paramName = Assert.Throws<ArgumentOutOfRangeException>(test).ParamName;
+            Assert.AreEqual("soilLayerIndex", paramName);
+        }
+
         [Test]
         [TestCase("A", 0)]
         [TestCase("B", 3)]
         [TestCase("Random", 5)]
-        public void CreateSoilLayerChartData_ValidSoilProfile_ReturnsEmptyChartDataCollectionWithDefaultStyling(string name, int soilLayerIndex)
+        public void CreateSoilLayerChartData_ValidSoilProfileAndSoilLayerIndex_ReturnsEmptyChartDataCollectionWithDefaultStyling(string name, int soilLayerIndex)
         {
             var surfaceLine = new RingtoetsPipingSurfaceLine();
             surfaceLine.SetGeometry(new[]