diff --git a/src/Avalonia.Dialogs/Internal/ByteSizeHelper.cs b/src/Avalonia.Dialogs/Internal/ByteSizeHelper.cs
index 3517f760b4..d8035daf40 100644
--- a/src/Avalonia.Dialogs/Internal/ByteSizeHelper.cs
+++ b/src/Avalonia.Dialogs/Internal/ByteSizeHelper.cs
@@ -1,10 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
 namespace Avalonia.Dialogs.Internal
 {
-	public static class ByteSizeHelper
+    internal static class ByteSizeHelper
 	{
 		private static readonly string[] Prefixes =
 		{
diff --git a/src/Avalonia.Dialogs/Internal/ChildFitter.cs b/src/Avalonia.Dialogs/Internal/ChildFitter.cs
index 6f9baff82f..5d0f89f3ac 100644
--- a/src/Avalonia.Dialogs/Internal/ChildFitter.cs
+++ b/src/Avalonia.Dialogs/Internal/ChildFitter.cs
@@ -4,7 +4,7 @@ using Avalonia.Layout;
 
 namespace Avalonia.Dialogs.Internal
 {
-	class ChildFitter : Decorator
+    internal class ChildFitter : Decorator
 	{
 		protected override Size MeasureOverride(Size availableSize)
 		{
diff --git a/src/Avalonia.Dialogs/Internal/FileSizeStringConverter.cs b/src/Avalonia.Dialogs/Internal/FileSizeStringConverter.cs
index 6de931c89d..e526932829 100644
--- a/src/Avalonia.Dialogs/Internal/FileSizeStringConverter.cs
+++ b/src/Avalonia.Dialogs/Internal/FileSizeStringConverter.cs
@@ -6,7 +6,7 @@ using System.Text;
 
 namespace Avalonia.Dialogs.Internal
 {
-	public class FileSizeStringConverter : IValueConverter
+    internal class FileSizeStringConverter : IValueConverter
 	{
 		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
 		{
diff --git a/src/Avalonia.Dialogs/Internal/InternalViewModelBase.cs b/src/Avalonia.Dialogs/Internal/InternalViewModelBase.cs
index 35e37eb810..2a8ae67ce1 100644
--- a/src/Avalonia.Dialogs/Internal/InternalViewModelBase.cs
+++ b/src/Avalonia.Dialogs/Internal/InternalViewModelBase.cs
@@ -5,7 +5,7 @@ using JetBrains.Annotations;
 
 namespace Avalonia.Dialogs.Internal
 {
-    class InternalViewModelBase : INotifyPropertyChanged
+    internal class InternalViewModelBase : INotifyPropertyChanged
     {
         public event PropertyChangedEventHandler PropertyChanged;
 
diff --git a/src/Avalonia.Dialogs/Internal/ManagedFileChooser.xaml.cs b/src/Avalonia.Dialogs/Internal/ManagedFileChooser.xaml.cs
index 7aba87115d..d476d226b0 100644
--- a/src/Avalonia.Dialogs/Internal/ManagedFileChooser.xaml.cs
+++ b/src/Avalonia.Dialogs/Internal/ManagedFileChooser.xaml.cs
@@ -10,7 +10,7 @@ using Avalonia.Markup.Xaml;
 
 namespace Avalonia.Dialogs.Internal
 {
-	class ManagedFileChooser : UserControl
+    internal class ManagedFileChooser : UserControl
 	{
 		private Control _quickLinksRoot;
 		private ListBox _filesView;
diff --git a/src/Avalonia.Dialogs/Internal/ManagedFileChooserFilterViewModel.cs b/src/Avalonia.Dialogs/Internal/ManagedFileChooserFilterViewModel.cs
index d54945ac60..b86b7a3f72 100644
--- a/src/Avalonia.Dialogs/Internal/ManagedFileChooserFilterViewModel.cs
+++ b/src/Avalonia.Dialogs/Internal/ManagedFileChooserFilterViewModel.cs
@@ -5,7 +5,7 @@ using Avalonia.Controls;
 
 namespace Avalonia.Dialogs.Internal
 {
-	class ManagedFileChooserFilterViewModel : InternalViewModelBase
+	internal class ManagedFileChooserFilterViewModel : InternalViewModelBase
 	{
 		private readonly string[] _extensions;
 		public string Name { get; }
diff --git a/src/Avalonia.Dialogs/Internal/ManagedFileChooserItemViewModel.cs b/src/Avalonia.Dialogs/Internal/ManagedFileChooserItemViewModel.cs
index b6535a93d0..306643b018 100644
--- a/src/Avalonia.Dialogs/Internal/ManagedFileChooserItemViewModel.cs
+++ b/src/Avalonia.Dialogs/Internal/ManagedFileChooserItemViewModel.cs
@@ -2,7 +2,7 @@ using System;
 
 namespace Avalonia.Dialogs.Internal
 {
-	class ManagedFileChooserItemViewModel : InternalViewModelBase
+    internal class ManagedFileChooserItemViewModel : InternalViewModelBase
 	{
 		private string _displayName;
 		private string _path;
diff --git a/src/Avalonia.Dialogs/Internal/ManagedFileChooserNavigationItem.cs b/src/Avalonia.Dialogs/Internal/ManagedFileChooserNavigationItem.cs
index b04a36692c..d3d5e2292b 100644
--- a/src/Avalonia.Dialogs/Internal/ManagedFileChooserNavigationItem.cs
+++ b/src/Avalonia.Dialogs/Internal/ManagedFileChooserNavigationItem.cs
@@ -1,6 +1,6 @@
 namespace Avalonia.Dialogs.Internal
 {
-	public class ManagedFileChooserNavigationItem
+    internal class ManagedFileChooserNavigationItem
 	{
 		public string DisplayName { get; set; }
 		public string Path { get; set; }
diff --git a/src/Avalonia.Dialogs/Internal/ManagedFileChooserSources.cs b/src/Avalonia.Dialogs/Internal/ManagedFileChooserSources.cs
index 84a3173eac..ad99206789 100644
--- a/src/Avalonia.Dialogs/Internal/ManagedFileChooserSources.cs
+++ b/src/Avalonia.Dialogs/Internal/ManagedFileChooserSources.cs
@@ -5,7 +5,7 @@ using System.Runtime.InteropServices;
 
 namespace Avalonia.Dialogs.Internal
 {
-	public class ManagedFileChooserSources
+    internal class ManagedFileChooserSources
 	{
 		public Func<ManagedFileChooserNavigationItem[]> GetUserDirectories { get; set; }
 			= DefaultGetUserDirectories;
diff --git a/src/Avalonia.Dialogs/Internal/ManagedFileChooserViewModel.cs b/src/Avalonia.Dialogs/Internal/ManagedFileChooserViewModel.cs
index 3977874e93..b6e61bd18e 100644
--- a/src/Avalonia.Dialogs/Internal/ManagedFileChooserViewModel.cs
+++ b/src/Avalonia.Dialogs/Internal/ManagedFileChooserViewModel.cs
@@ -2,16 +2,14 @@ using System;
 using System.Collections.Specialized;
 using System.IO;
 using System.Linq;
-using System.Reactive;
 using System.Runtime.InteropServices;
 using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Threading;
-using ReactiveUI;
 
 namespace Avalonia.Dialogs.Internal
 {
-    class ManagedFileChooserViewModel : InternalViewModelBase
+    internal class ManagedFileChooserViewModel : InternalViewModelBase
 	{
 		public event Action CancelRequested;
 		public event Action<string[]> CompleteRequested;
diff --git a/src/Avalonia.Dialogs/Internal/ResourceSelectorConverter.cs b/src/Avalonia.Dialogs/Internal/ResourceSelectorConverter.cs
index 8346ba952c..11ef6c0f5b 100644
--- a/src/Avalonia.Dialogs/Internal/ResourceSelectorConverter.cs
+++ b/src/Avalonia.Dialogs/Internal/ResourceSelectorConverter.cs
@@ -5,7 +5,7 @@ using Avalonia.Data.Converters;
 
 namespace Avalonia.Dialogs.Internal
 {
-	public class ResourceSelectorConverter : ResourceDictionary, IValueConverter
+    internal class ResourceSelectorConverter : ResourceDictionary, IValueConverter
 	{
 		public object Convert(object key, Type targetType, object parameter, CultureInfo culture)
 		{