Index: Ringtoets/Common/src/Ringtoets.Common.IO/Structures/StructuresParameterRowsValidator.cs
===================================================================
diff -u -rb70abd70f1cd326d1a753c5879a065149ac2ae84 -r5e19ee5ddd92f11deae38f4ce957ff16071ec144
--- Ringtoets/Common/src/Ringtoets.Common.IO/Structures/StructuresParameterRowsValidator.cs	(.../StructuresParameterRowsValidator.cs)	(revision b70abd70f1cd326d1a753c5879a065149ac2ae84)
+++ Ringtoets/Common/src/Ringtoets.Common.IO/Structures/StructuresParameterRowsValidator.cs	(.../StructuresParameterRowsValidator.cs)	(revision 5e19ee5ddd92f11deae38f4ce957ff16071ec144)
@@ -346,7 +346,7 @@
             List<string> messages = new List<string>();
 
             double mean = row.NumericalValue;
-            if (double.IsNaN(mean) || double.IsInfinity(mean) || (!meanMustBeGreaterThanZero || mean <= 0))
+            if (double.IsNaN(mean) || double.IsInfinity(mean) || (meanMustBeGreaterThanZero && mean <= 0))
             {
                 messages.Add(string.Format(Resources.StructuresParameterRowsValidator_Line_0_column_1_value_invalid, row.LineNumber, numericalValueColumn));
             }