diff --git a/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableValidatorValidateAllPropertiesGenerator.cs b/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableValidatorValidateAllPropertiesGenerator.cs
index 320db7f0f..3fdbf8aaa 100644
--- a/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableValidatorValidateAllPropertiesGenerator.cs
+++ b/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableValidatorValidateAllPropertiesGenerator.cs
@@ -21,31 +21,43 @@ public sealed partial class ObservableValidatorValidateAllPropertiesGenerator :
     /// <inheritdoc/>
     public void Initialize(IncrementalGeneratorInitializationContext context)
     {
-        // Get all class declarations. We intentionally skip generating code for abstract types, as that would never be used.
-        // The methods that are generated by this generator are retrieved through reflection using the type of the invoking
-        // instance as discriminator, which means a type that is abstract could never be used (since it couldn't be instantiated).
-        IncrementalValuesProvider<INamedTypeSymbol> typeSymbols =
+        // Get the types that inherit from ObservableValidator and gather their info
+        IncrementalValuesProvider<ValidationInfo> validationInfo =
             context.SyntaxProvider
             .CreateSyntaxProvider(
                 static (node, _) => node is ClassDeclarationSyntax,
-                static (context, _) =>
+                static (context, token) =>
                 {
                     if (!context.SemanticModel.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))
                     {
                         return default;
                     }
 
-                    return (context.Node, Symbol: (INamedTypeSymbol)context.SemanticModel.GetDeclaredSymbol(context.Node)!);
-                })
-            .Where(static item => item.Symbol is { IsAbstract: false, IsGenericType: false } && item.Node.IsFirstSyntaxDeclarationForSymbol(item.Symbol))
-            .Select(static (item, _) => item.Symbol);
+                    INamedTypeSymbol typeSymbol = (INamedTypeSymbol)context.SemanticModel.GetDeclaredSymbol(context.Node, token)!;
 
-        // Get the types that inherit from ObservableValidator and gather their info
-        IncrementalValuesProvider<ValidationInfo> validationInfo =
-            typeSymbols
-            .Where(Execute.IsObservableValidator)
-            .Select(static (item, _) => Execute.GetInfo(item))
-            .WithComparer(ValidationInfo.Comparer.Default);
+                    // Skip generating code for abstract types, as that would never be used. The methods that are generated by
+                    // this generator are retrieved through reflection using the type of the invoking instance as discriminator,
+                    // which means a type that is abstract could never be used (since it couldn't be instantiated).
+                    if (typeSymbol is not { IsAbstract: false, IsGenericType: false })
+                    {
+                        return default;
+                    }
+
+                    // Just like in IMessengerRegisterAllGenerator, only select the first declaration for this type symbol
+                    if (!context.Node.IsFirstSyntaxDeclarationForSymbol(typeSymbol))
+                    {
+                        return default;
+                    }
+
+                    // Only select types inheriting from ObservableValidator
+                    if (!Execute.IsObservableValidator(typeSymbol))
+                    {
+                        return default;
+                    }
+
+                    return Execute.GetInfo(typeSymbol);
+                })
+            .Where(static item => item is not null)!;
 
         // Check whether the header file is needed
         IncrementalValueProvider<bool> isHeaderFileNeeded =