Index: Ringtoets/Piping/src/Ringtoets.Piping.IO/SurfaceLines/CharacteristicPointsCsvReader.cs
===================================================================
diff -u -r8e182435811ddd7f9cf29ae57f62b91a2ce5a29c -r7ae9100ff4e61169edcefaeb01b72d492431742f
--- Ringtoets/Piping/src/Ringtoets.Piping.IO/SurfaceLines/CharacteristicPointsCsvReader.cs	(.../CharacteristicPointsCsvReader.cs)	(revision 8e182435811ddd7f9cf29ae57f62b91a2ce5a29c)
+++ Ringtoets/Piping/src/Ringtoets.Piping.IO/SurfaceLines/CharacteristicPointsCsvReader.cs	(.../CharacteristicPointsCsvReader.cs)	(revision 7ae9100ff4e61169edcefaeb01b72d492431742f)
@@ -253,12 +253,10 @@
                 return false;
             }
 
-            foreach (string column in tokenizedHeader.Where(c => c.StartsWith(xPrefix)))
+            if (tokenizedHeader.Where(c => c.StartsWith(xPrefix))
+                               .Any(c => !DetermineRequiredYZColumns(c, tokenizedHeader)))
             {
-                if (!DetermineRequiredYZColumns(column, tokenizedHeader))
-                {
-                    return false;
-                }
+                return false;
             }
 
             DetermineOrderColumn(tokenizedHeader);