Index: Ringtoets/Common/src/Ringtoets.Common.Data/IllustrationPoints/GeneralResult.cs
===================================================================
diff -u -r383978e113c1829e86c866ac075a476fa7e07086 -r2e944cbf52d124fd501ed4ed8e991aa50299cc69
--- Ringtoets/Common/src/Ringtoets.Common.Data/IllustrationPoints/GeneralResult.cs	(.../GeneralResult.cs)	(revision 383978e113c1829e86c866ac075a476fa7e07086)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/IllustrationPoints/GeneralResult.cs	(.../GeneralResult.cs)	(revision 2e944cbf52d124fd501ed4ed8e991aa50299cc69)
@@ -152,7 +152,7 @@
         private static void ValidateTopLevelIllustrationPoints(IEnumerable<T> topLevelIllustrationPoints)
         {
             bool hasNonDistinctIllustrationPointsPerWindDirection =
-                topLevelIllustrationPoints.AnyNonDistinct(t => $"{t.ClosingSituation} {t.WindDirection.Angle}");
+                topLevelIllustrationPoints.HasDuplicates(t => $"{t.ClosingSituation} {t.WindDirection.Angle}");
             if (hasNonDistinctIllustrationPointsPerWindDirection)
             {
                 throw new ArgumentException(string.Format(Resources.GeneralResult_Imported_non_unique_closing_situations_or_wind_direction));
@@ -161,7 +161,7 @@
 
         private static void ValidateStochasts(IEnumerable<Stochast> stochasts)
         {
-            bool hasNonDistinctStochasts = stochasts.AnyNonDistinct(s => s.Name);
+            bool hasNonDistinctStochasts = stochasts.HasDuplicates(s => s.Name);
             if (hasNonDistinctStochasts)
             {
                 throw new ArgumentException(string.Format(Resources.GeneralResult_Imported_non_unique_stochasts));