Index: Ringtoets/Common/src/Ringtoets.Common.Data/Hydraulics/HydraulicBoundaryCalculationSettings.cs
===================================================================
diff -u -r3ff86742b1fa9935c42f90d951df9c20bbbf7b8f -rb12ecfa720b31478b315592d309261027d1ac7ce
--- Ringtoets/Common/src/Ringtoets.Common.Data/Hydraulics/HydraulicBoundaryCalculationSettings.cs	(.../HydraulicBoundaryCalculationSettings.cs)	(revision 3ff86742b1fa9935c42f90d951df9c20bbbf7b8f)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/Hydraulics/HydraulicBoundaryCalculationSettings.cs	(.../HydraulicBoundaryCalculationSettings.cs)	(revision b12ecfa720b31478b315592d309261027d1ac7ce)
@@ -1,23 +1,34 @@
 namespace Ringtoets.Common.Data.Hydraulics
 {
     /// <summary>
-    /// Class which holds all hydraulic boundary calculations settings.
+    /// Class which holds all hydraulic boundary calculation settings.
     /// </summary>
     public class HydraulicBoundaryCalculationSettings
     {
         /// <summary>
         /// Creates a new instance of <see cref="HydraulicBoundaryCalculationSettings"/>.
         /// </summary>
         /// <param name="hydraulicBoundaryDatabaseFilePath">The file path of the hydraulic boundary database.</param>
-        /// <param name="hlcdFilePath">The file path to the hlcd.</param>
         /// <param name="preprocessorDirectory">The preprocessor directory.</param>
+        public HydraulicBoundaryCalculationSettings(string hydraulicBoundaryDatabaseFilePath, string preprocessorDirectory)
+
+        {
+            HydraulicBoundaryDatabaseFilePath = hydraulicBoundaryDatabaseFilePath;
+            PreprocessorDirectory = preprocessorDirectory;
+        }
+
+        /// <summary>
+        /// Creates a new instance of <see cref="HydraulicBoundaryCalculationSettings"/>.
+        /// </summary>
+        /// <param name="hydraulicBoundaryDatabaseFilePath">The file path of the hydraulic boundary database.</param>
+        /// <param name="hlcdFilePath">The file path of the hlcd.</param>
+        /// <param name="preprocessorDirectory">The preprocessor directory.</param>
         public HydraulicBoundaryCalculationSettings(string hydraulicBoundaryDatabaseFilePath,
                                                     string hlcdFilePath,
                                                     string preprocessorDirectory)
+            : this(hydraulicBoundaryDatabaseFilePath, preprocessorDirectory)
         {
-            HydraulicBoundaryDatabaseFilePath = hydraulicBoundaryDatabaseFilePath;
             HlcdFilePath = hlcdFilePath;
-            PreprocessorDirectory = preprocessorDirectory;
         }
 
         /// <summary>
@@ -26,7 +37,7 @@
         public string HydraulicBoundaryDatabaseFilePath { get; }
 
         /// <summary>
-        /// Gets the HLCD file path.
+        /// Gets the hlcd file path.
         /// </summary>
         public string HlcdFilePath { get; }
 
Index: Ringtoets/Common/src/Ringtoets.Common.Data/Hydraulics/HydraulicBoundaryCalculationSettingsFactory.cs
===================================================================
diff -u -r3ff86742b1fa9935c42f90d951df9c20bbbf7b8f -rb12ecfa720b31478b315592d309261027d1ac7ce
--- Ringtoets/Common/src/Ringtoets.Common.Data/Hydraulics/HydraulicBoundaryCalculationSettingsFactory.cs	(.../HydraulicBoundaryCalculationSettingsFactory.cs)	(revision 3ff86742b1fa9935c42f90d951df9c20bbbf7b8f)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/Hydraulics/HydraulicBoundaryCalculationSettingsFactory.cs	(.../HydraulicBoundaryCalculationSettingsFactory.cs)	(revision b12ecfa720b31478b315592d309261027d1ac7ce)
@@ -14,7 +14,7 @@
         /// </summary>
         /// <param name="hydraulicBoundaryDatabase">The <see cref="HydraulicBoundaryDatabase"/>
         /// to create a <see cref="HydraulicBoundaryCalculationSettings"/> for.</param>
-        /// <returns>The <see cref="HydraulicBoundaryCalculationSettings"/>.</returns>
+        /// <returns>A <see cref="HydraulicBoundaryCalculationSettings"/>.</returns>
         public static HydraulicBoundaryCalculationSettings CreateSettings(HydraulicBoundaryDatabase hydraulicBoundaryDatabase)
         {
             if (hydraulicBoundaryDatabase == null)
@@ -23,17 +23,18 @@
             }
 
             string hydraulicBoundaryDatabaseFilePath = hydraulicBoundaryDatabase.FilePath;
-            string hlcdFilePath = null;
-
-            if (!string.IsNullOrWhiteSpace(hydraulicBoundaryDatabaseFilePath))
+            string effectivePreprocessorDirectory = hydraulicBoundaryDatabase.EffectivePreprocessorDirectory();
+            if (string.IsNullOrWhiteSpace(hydraulicBoundaryDatabaseFilePath))
             {
-                string directory = Path.GetDirectoryName(hydraulicBoundaryDatabaseFilePath);
-                hlcdFilePath = Path.Combine(directory, "HLCD.sqlite");
+                return new HydraulicBoundaryCalculationSettings(hydraulicBoundaryDatabaseFilePath, 
+                    effectivePreprocessorDirectory);
             }
 
+            string directory = Path.GetDirectoryName(hydraulicBoundaryDatabaseFilePath);
+            string hlcdFilePath = Path.Combine(directory, "HLCD.sqlite");
             return new HydraulicBoundaryCalculationSettings(hydraulicBoundaryDatabaseFilePath,
                                                             hlcdFilePath,
-                                                            hydraulicBoundaryDatabase.EffectivePreprocessorDirectory());
+                                                            effectivePreprocessorDirectory);
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/Common/test/Ringtoets.Common.Data.Test/Hydraulics/HydraulicBoundaryCalculationSettingsTest.cs
===================================================================
diff -u -r59c26a72b1017bdb20e45a2301d8a109f5f16f5f -rb12ecfa720b31478b315592d309261027d1ac7ce
--- Ringtoets/Common/test/Ringtoets.Common.Data.Test/Hydraulics/HydraulicBoundaryCalculationSettingsTest.cs	(.../HydraulicBoundaryCalculationSettingsTest.cs)	(revision 59c26a72b1017bdb20e45a2301d8a109f5f16f5f)
+++ Ringtoets/Common/test/Ringtoets.Common.Data.Test/Hydraulics/HydraulicBoundaryCalculationSettingsTest.cs	(.../HydraulicBoundaryCalculationSettingsTest.cs)	(revision b12ecfa720b31478b315592d309261027d1ac7ce)
@@ -8,7 +8,7 @@
     public class HydraulicBoundaryCalculationSettingsTest
     {
         [Test]
-        [TestCaseSource(nameof(GetTestCases))]
+        [TestCaseSource(nameof(GetTestCasesWithAllParameters))]
         public void Constructor_WithArguments_ExpectedValues(string hydraulicBoundaryDatabaseFilePath,
                                                              string hlcdFilePath,
                                                              string preprocessorDirectory)
@@ -24,8 +24,23 @@
             Assert.AreEqual(preprocessorDirectory, settings.PreprocessorDirectory);
         }
 
-        private static IEnumerable<TestCaseData> GetTestCases()
+        [Test]
+        [TestCaseSource(nameof(GetTestCaseWithoutHlcdParameter))]
+        public void Constructor_ExpectedValues(string hydraulicBoundaryDatabaseFilePath,
+                                               string preprocessorDirectory)
         {
+            // Call
+            var settings = new HydraulicBoundaryCalculationSettings(hydraulicBoundaryDatabaseFilePath,
+                                                                    preprocessorDirectory);
+
+            // Assert
+            Assert.AreEqual(hydraulicBoundaryDatabaseFilePath, settings.HydraulicBoundaryDatabaseFilePath);
+            Assert.IsNull(settings.HlcdFilePath);
+            Assert.AreEqual(preprocessorDirectory, settings.PreprocessorDirectory);
+        }
+
+        private static IEnumerable<TestCaseData> GetTestCasesWithAllParameters()
+        {
             yield return new TestCaseData("D:\\HydraulicBoundaryDatabase.sqlite",
                                           "D:\\HLCD.sqlite",
                                           "D:\\")
@@ -37,5 +52,18 @@
             yield return new TestCaseData(null, null, null)
                 .SetName("All inputs null");
         }
+
+        private static IEnumerable<TestCaseData> GetTestCaseWithoutHlcdParameter()
+        {
+            yield return new TestCaseData("D:\\HydraulicBoundaryDatabase.sqlite",
+                                          "D:\\")
+                .SetName("All inputs with values");
+            yield return new TestCaseData("  ", "  ")
+                .SetName("All inputs whitespace");
+            yield return new TestCaseData(string.Empty, string.Empty)
+                .SetName("All inputs empty");
+            yield return new TestCaseData(null, null)
+                .SetName("All inputs null");
+        }
     }
 }
\ No newline at end of file
Index: Ringtoets/Common/test/Ringtoets.Common.Service.TestUtil/HydraRingCalculationSettingsTestHelper.cs
===================================================================
diff -u -raa7331d7072b48e96c923dc10d349ba0731b918b -rb12ecfa720b31478b315592d309261027d1ac7ce
--- Ringtoets/Common/test/Ringtoets.Common.Service.TestUtil/HydraRingCalculationSettingsTestHelper.cs	(.../HydraRingCalculationSettingsTestHelper.cs)	(revision aa7331d7072b48e96c923dc10d349ba0731b918b)
+++ Ringtoets/Common/test/Ringtoets.Common.Service.TestUtil/HydraRingCalculationSettingsTestHelper.cs	(.../HydraRingCalculationSettingsTestHelper.cs)	(revision b12ecfa720b31478b315592d309261027d1ac7ce)
@@ -5,7 +5,7 @@
 namespace Ringtoets.Common.Service.TestUtil
 {
     /// <summary>
-    /// A test helper which can be used to assert instances of <see cref="HydraRingCalculationSettings"/>
+    /// A test helper which can be used to assert instances of <see cref="HydraRingCalculationSettings"/>.
     /// </summary>
     public static class HydraRingCalculationSettingsTestHelper
     {