diff --git a/src/CommandLineUtils/HelpText/DefaultHelpTextGenerator.cs b/src/CommandLineUtils/HelpText/DefaultHelpTextGenerator.cs
index 1875d3d9..763a1e35 100644
--- a/src/CommandLineUtils/HelpText/DefaultHelpTextGenerator.cs
+++ b/src/CommandLineUtils/HelpText/DefaultHelpTextGenerator.cs
@@ -194,7 +194,7 @@ protected virtual void GenerateArguments(
                     var description = arg.Description;
                     var allowedValuesBeenSet = false;
 
-                    foreach (var attributeValidator in arg.Validators.Cast<AttributeValidator>())
+                    foreach (var attributeValidator in arg.Validators.OfType<AttributeValidator>())
                     {
                         if (attributeValidator?.ValidationAttribute is AllowedValuesAttribute allowedValuesAttribute)
                         {
@@ -251,7 +251,7 @@ protected virtual void GenerateOptions(
                     var description = opt.Description;
                     var allowedValuesBeenSet = false;
 
-                    foreach (var attributeValidator in opt.Validators.Cast<AttributeValidator>())
+                    foreach (var attributeValidator in opt.Validators.OfType<AttributeValidator>())
                     {
                         if (attributeValidator?.ValidationAttribute is AllowedValuesAttribute allowedValuesAttribute)
                         {