Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingSoilLayerTest.cs
===================================================================
diff -u -ra7ba75d934df79407c6fa412f904289034bc0262 -re42bdf3dd379c46bab9212eb7b30f4754c9bc91c
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingSoilLayerTest.cs	(.../PipingSoilLayerTest.cs)	(revision a7ba75d934df79407c6fa412f904289034bc0262)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/PipingSoilLayerTest.cs	(.../PipingSoilLayerTest.cs)	(revision e42bdf3dd379c46bab9212eb7b30f4754c9bc91c)
@@ -67,7 +67,7 @@
             TestDelegate test = () => layer.MaterialName = null;
 
             // Assert
-            var paramName = Assert.Throws<ArgumentNullException>(test).ParamName;
+            string paramName = Assert.Throws<ArgumentNullException>(test).ParamName;
             Assert.AreEqual("value", paramName);
         }