diff --git a/src/LightObjects.Generated/GeneratedIdentifierSourceGenerator.cs b/src/LightObjects.Generated/GeneratedIdentifierSourceGenerator.cs
index 25b2473..b1f92fa 100644
--- a/src/LightObjects.Generated/GeneratedIdentifierSourceGenerator.cs
+++ b/src/LightObjects.Generated/GeneratedIdentifierSourceGenerator.cs
@@ -57,7 +57,7 @@ namespace {AttributesNamespace};
                       /// The underlying type to use as the strongly typed identifier.
                       /// </typeparam>
                       [AttributeUsage(AttributeTargets.Struct | AttributeTargets.Class)]
-                      public sealed class {GeneratedIdentifierAttributeName}<TIdentifier> : Attribute;
+                      internal sealed class {GeneratedIdentifierAttributeName}<TIdentifier> : Attribute;
                       """;
         context.AddSource(GeneratedIdentifierAttributeHint, SourceText.From(source, Encoding.UTF8));
     }
diff --git a/tests/LightObjects.Generated.Tests/GeneratedIdentifierSourceGeneratorTests.cs b/tests/LightObjects.Generated.Tests/GeneratedIdentifierSourceGeneratorTests.cs
index ae21795..2460403 100644
--- a/tests/LightObjects.Generated.Tests/GeneratedIdentifierSourceGeneratorTests.cs
+++ b/tests/LightObjects.Generated.Tests/GeneratedIdentifierSourceGeneratorTests.cs
@@ -125,7 +125,7 @@ namespace MyProject.Identifiers;
                      namespace LightObjects.Generated;
 
                      [AttributeUsage(AttributeTargets.Struct | AttributeTargets.Class)]
-                     public sealed class GeneratedIdentifierAttribute<TIdentifier> : Attribute;
+                     internal sealed class GeneratedIdentifierAttribute<TIdentifier> : Attribute;
                      """;
     }