diff --git a/src/Features/CSharpTest/Copilot/CSharpImplementNotImplementedExceptionFixProviderTests.cs b/src/Features/CSharpTest/Copilot/CSharpImplementNotImplementedExceptionFixProviderTests.cs
index 1bd47a290ce1f..242228c5e8c45 100644
--- a/src/Features/CSharpTest/Copilot/CSharpImplementNotImplementedExceptionFixProviderTests.cs
+++ b/src/Features/CSharpTest/Copilot/CSharpImplementNotImplementedExceptionFixProviderTests.cs
@@ -410,71 +410,6 @@ public interface IDataService
         .RunAsync();
     }
 
-    [Fact]
-    public async Task HandleInvalidCode_SuggestsAsComment()
-    {
-        await new CustomCompositionCSharpTest
-        {
-            CodeFixTestBehaviors = CodeFixTestBehaviors.FixOne,
-            TestCode = """
-            using System;
-
-            class C
-            {
-                void M()
-                {
-                    {|IDE3000:throw new NotImplementedException();|}
-                }
-            }
-            """,
-            FixedCode = """
-            using System;
-
-            class C
-            {
-                /* The generated implementation isn't a valid method or property:
-                using System;
-                class C
-                {
-                    void M()
-                    {
-                        throw new NotImplementedException();
-                    }
-                } */
-                void M()
-                {
-                    {|IDE3000:throw new NotImplementedException();|}
-                }
-            }
-            """,
-            FixedState =
-            {
-                MarkupHandling = MarkupMode.Allow,
-            },
-            LanguageVersion = LanguageVersion.CSharp11,
-            ReferenceAssemblies = ReferenceAssemblies.Net.Net60,
-        }
-        .WithMockCopilotService(copilotService =>
-        {
-            var replacement = """
-            using System;
-            class C
-            {
-                void M()
-                {
-                    throw new NotImplementedException();
-                }
-            }
-            """;
-            copilotService.PrepareUsingSingleFakeResult = new()
-            {
-                ReplacementNode = SyntaxFactory.ParseCompilationUnit(replacement),
-                Message = $"The generated implementation isn't a valid method or property:{Environment.NewLine}{replacement}",
-            };
-        })
-        .RunAsync();
-    }
-
     [Fact]
     public async Task ReplacementNode_Null_NotifiesWithComment()
     {
diff --git a/src/Features/Core/Portable/Copilot/ImplementationDetails.cs b/src/Features/Core/Portable/Copilot/ImplementationDetails.cs
index 3d001e1e8cc71..1aefe4c870155 100644
--- a/src/Features/Core/Portable/Copilot/ImplementationDetails.cs
+++ b/src/Features/Core/Portable/Copilot/ImplementationDetails.cs
@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
 namespace Microsoft.CodeAnalysis.Copilot;
 
 /// <summary>
@@ -16,7 +18,7 @@ internal sealed class ImplementationDetails
     public string? Message { get; init; }
 
     /// <summary>
-    /// Gets the replacement syntax node. Either this property or <see cref="Message"/> must be set.
+    /// Gets the replacement node. Either this property or <see cref="Message"/> must be set.
     /// </summary>
-    public SyntaxNode? ReplacementNode { get; init; }
+    public MemberDeclarationSyntax? ReplacementNode { get; init; }
 }
diff --git a/src/Features/ExternalAccess/Copilot/GenerateImplementation/ImplementationDetailsWrapper.cs b/src/Features/ExternalAccess/Copilot/GenerateImplementation/ImplementationDetailsWrapper.cs
index 9cfcb8bdf5c4b..43190dc393ed1 100644
--- a/src/Features/ExternalAccess/Copilot/GenerateImplementation/ImplementationDetailsWrapper.cs
+++ b/src/Features/ExternalAccess/Copilot/GenerateImplementation/ImplementationDetailsWrapper.cs
@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
 namespace Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation;
 
 /// <summary>
@@ -18,5 +20,5 @@ internal sealed class ImplementationDetailsWrapper
     /// <summary>
     /// Gets the replacement syntax node. Either this property or <see cref="Message"/> must be set.
     /// </summary>
-    public SyntaxNode? ReplacementNode { get; init; }
+    public MemberDeclarationSyntax? ReplacementNode { get; init; }
 }
diff --git a/src/Features/ExternalAccess/Copilot/InternalAPI.Unshipped.txt b/src/Features/ExternalAccess/Copilot/InternalAPI.Unshipped.txt
index 52c76edce89ff..485c3b9368dd8 100644
--- a/src/Features/ExternalAccess/Copilot/InternalAPI.Unshipped.txt
+++ b/src/Features/ExternalAccess/Copilot/InternalAPI.Unshipped.txt
@@ -35,7 +35,7 @@ Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation.Implementat
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation.ImplementationDetailsWrapper.ImplementationDetailsWrapper() -> void
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation.ImplementationDetailsWrapper.Message.get -> string?
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation.ImplementationDetailsWrapper.Message.init -> void
-Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation.ImplementationDetailsWrapper.ReplacementNode.get -> Microsoft.CodeAnalysis.SyntaxNode?
+Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation.ImplementationDetailsWrapper.ReplacementNode.get -> Microsoft.CodeAnalysis.CSharp.Syntax.MemberDeclarationSyntax?
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.GenerateImplementation.ImplementationDetailsWrapper.ReplacementNode.init -> void
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.IExternalCSharpCopilotCodeAnalysisService
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.IExternalCSharpCopilotCodeAnalysisService.AnalyzeDocumentAsync(Microsoft.CodeAnalysis.Document! document, Microsoft.CodeAnalysis.Text.TextSpan? span, string! promptTitle, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.Diagnostic!>>!