Index: Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Services/HydraRingInitializationServiceTest.cs
===================================================================
diff -u -r16d6d5ad38a45e4e0e8b3a9b41b3383d31595a36 -re3f9dffa91a0def0b6e6bc7dfabef74cc64745c5
--- Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Services/HydraRingInitializationServiceTest.cs	(.../HydraRingInitializationServiceTest.cs)	(revision 16d6d5ad38a45e4e0e8b3a9b41b3383d31595a36)
+++ Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Services/HydraRingInitializationServiceTest.cs	(.../HydraRingInitializationServiceTest.cs)	(revision e3f9dffa91a0def0b6e6bc7dfabef74cc64745c5)
@@ -31,7 +31,7 @@
     [TestFixture]
     public class HydraRingInitializationServiceTest
     {
-        private string hydraRingDirectory = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), @"HydraRing");
+        private readonly string hydraRingDirectory = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), @"HydraRing");
 
         [Test]
         public void ParameteredConstructor_ExpectedValues()