diff --git a/ILSpy/TreeNodes/AssemblyReferenceTreeNode.cs b/ILSpy/TreeNodes/AssemblyReferenceTreeNode.cs
index 892418522..5b7f99bad 100644
--- a/ILSpy/TreeNodes/AssemblyReferenceTreeNode.cs
+++ b/ILSpy/TreeNodes/AssemblyReferenceTreeNode.cs
@@ -41,7 +41,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// using ILAmbience escaping plus a generic assembly icon. Children (the
 	/// per-reference type list and transitive references) are not yet implemented.
 	/// </summary>
-	sealed class AssemblyReferenceTreeNode : ILSpyTreeNode
+	public sealed class AssemblyReferenceTreeNode : ILSpyTreeNode
 	{
 		enum LoadState { Unloaded, Loading, Loaded, Failed }
 
diff --git a/ILSpy/TreeNodes/AssemblyTreeNode.cs b/ILSpy/TreeNodes/AssemblyTreeNode.cs
index 7af1f3734..9e9eae875 100644
--- a/ILSpy/TreeNodes/AssemblyTreeNode.cs
+++ b/ILSpy/TreeNodes/AssemblyTreeNode.cs
@@ -42,7 +42,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class AssemblyTreeNode : ILSpyTreeNode
+	public sealed class AssemblyTreeNode : ILSpyTreeNode
 	{
 		readonly LoadedAssembly assembly;
 		string? loadError;
diff --git a/ILSpy/TreeNodes/EventTreeNode.cs b/ILSpy/TreeNodes/EventTreeNode.cs
index 7dac3351b..21e3b145a 100644
--- a/ILSpy/TreeNodes/EventTreeNode.cs
+++ b/ILSpy/TreeNodes/EventTreeNode.cs
@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class EventTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class EventTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IEvent EventDefinition { get; }
 
diff --git a/ILSpy/TreeNodes/ExtensionTreeNode.cs b/ILSpy/TreeNodes/ExtensionTreeNode.cs
index 9c7d5d455..1d9449c2c 100644
--- a/ILSpy/TreeNodes/ExtensionTreeNode.cs
+++ b/ILSpy/TreeNodes/ExtensionTreeNode.cs
@@ -39,7 +39,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// methods/properties; the block's own members (methods + properties) appear as
 	/// children of this node when expanded.
 	/// </summary>
-	internal sealed class ExtensionTreeNode : ILSpyTreeNode
+	public sealed class ExtensionTreeNode : ILSpyTreeNode
 	{
 		public ExtensionTreeNode(
 			ITypeDefinition typeDefinition,
diff --git a/ILSpy/TreeNodes/FieldTreeNode.cs b/ILSpy/TreeNodes/FieldTreeNode.cs
index 509d9cfc8..523ad263e 100644
--- a/ILSpy/TreeNodes/FieldTreeNode.cs
+++ b/ILSpy/TreeNodes/FieldTreeNode.cs
@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class FieldTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class FieldTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IField FieldDefinition { get; }
 
diff --git a/ILSpy/TreeNodes/MethodTreeNode.cs b/ILSpy/TreeNodes/MethodTreeNode.cs
index b59245410..210b3a1a5 100644
--- a/ILSpy/TreeNodes/MethodTreeNode.cs
+++ b/ILSpy/TreeNodes/MethodTreeNode.cs
@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class MethodTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class MethodTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IMethod MethodDefinition { get; }
 
diff --git a/ILSpy/TreeNodes/NamespaceTreeNode.cs b/ILSpy/TreeNodes/NamespaceTreeNode.cs
index 2262394e1..4cdb51fbe 100644
--- a/ILSpy/TreeNodes/NamespaceTreeNode.cs
+++ b/ILSpy/TreeNodes/NamespaceTreeNode.cs
@@ -29,7 +29,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class NamespaceTreeNode : ILSpyTreeNode
+	public sealed class NamespaceTreeNode : ILSpyTreeNode
 	{
 		readonly string name;
 		readonly string fullName;
diff --git a/ILSpy/TreeNodes/NaturalStringComparer.cs b/ILSpy/TreeNodes/NaturalStringComparer.cs
index b5bc384a0..b4cea596a 100644
--- a/ILSpy/TreeNodes/NaturalStringComparer.cs
+++ b/ILSpy/TreeNodes/NaturalStringComparer.cs
@@ -24,7 +24,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// <summary>
 	/// .NET natural string comparison.
 	/// </summary>
-	internal static class NaturalStringComparer
+	public static class NaturalStringComparer
 	{
 		public static readonly IComparer<string> Instance =
 			System.StringComparer.Create(CultureInfo.CurrentCulture, CompareOptions.NumericOrdering);
diff --git a/ILSpy/TreeNodes/PropertyTreeNode.cs b/ILSpy/TreeNodes/PropertyTreeNode.cs
index 1b227160d..4e50563ec 100644
--- a/ILSpy/TreeNodes/PropertyTreeNode.cs
+++ b/ILSpy/TreeNodes/PropertyTreeNode.cs
@@ -28,7 +28,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class PropertyTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class PropertyTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		public IProperty PropertyDefinition { get; }
 
diff --git a/ILSpy/TreeNodes/TypeTreeNode.cs b/ILSpy/TreeNodes/TypeTreeNode.cs
index 50b90a534..ae3e3fcfa 100644
--- a/ILSpy/TreeNodes/TypeTreeNode.cs
+++ b/ILSpy/TreeNodes/TypeTreeNode.cs
@@ -33,7 +33,7 @@ using ICSharpCode.ILSpy.Languages;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class TypeTreeNode : ILSpyTreeNode, IMemberTreeNode
+	public sealed class TypeTreeNode : ILSpyTreeNode, IMemberTreeNode
 	{
 		readonly TypeDefinitionHandle handle;
 		readonly MetadataFile module;