Index: Ringtoets/Piping/src/Ringtoets.Piping.IO/Importers/PipingConfigurationImporter.cs
===================================================================
diff -u -rf9b356c4654ac261a1ec41255f872dcaba9ac7a6 -r5762f5a734abc237f01cd62257cedd7ba2e9c8e8
--- Ringtoets/Piping/src/Ringtoets.Piping.IO/Importers/PipingConfigurationImporter.cs	(.../PipingConfigurationImporter.cs)	(revision f9b356c4654ac261a1ec41255f872dcaba9ac7a6)
+++ Ringtoets/Piping/src/Ringtoets.Piping.IO/Importers/PipingConfigurationImporter.cs	(.../PipingConfigurationImporter.cs)	(revision 5762f5a734abc237f01cd62257cedd7ba2e9c8e8)
@@ -259,16 +259,24 @@
         /// <exception cref="CriticalFileValidationException">Thrown when the entry point or exit point is invalid.</exception>
         private static void ReadEntryExitPoint(ReadPipingCalculation readCalculation, PipingCalculationScenario pipingCalculation)
         {
-            if (readCalculation.EntryPointL.HasValue)
+            bool hasEntryPoint = readCalculation.EntryPointL.HasValue;
+            bool hasExitPoint = readCalculation.ExitPointL.HasValue;
+
+            if (readCalculation.SurfaceLine == null && (hasEntryPoint || hasExitPoint))
             {
+                throw new CriticalFileValidationException(Resources.PipingConfigurationImporter_ReadSurfaceLine_EntryPointL_or_ExitPointL_defined_without_SurfaceLine);
+            }
+
+            if (hasEntryPoint)
+            {
                 var entryPoint = (double) readCalculation.EntryPointL;
 
                 PerformActionHandlingAnyArgumentOutOfRangeException(
                     () => pipingCalculation.InputParameters.EntryPointL = (RoundedDouble) entryPoint,
                     string.Format(Resources.PipingConfigurationImporter_ReadEntryExitPoint_Entry_point_invalid, entryPoint));
             }
 
-            if (readCalculation.ExitPointL.HasValue)
+            if (hasExitPoint)
             {
                 var exitPoint = (double) readCalculation.ExitPointL;