diff --git a/src/Avalonia.Native/CallbackBase.cs b/src/Avalonia.Native/CallbackBase.cs
index 2d875dbc0e..9f59c97f9b 100644
--- a/src/Avalonia.Native/CallbackBase.cs
+++ b/src/Avalonia.Native/CallbackBase.cs
@@ -6,7 +6,7 @@ using MicroCom.Runtime;
 
 namespace Avalonia.Native
 {
-    public abstract class NativeCallbackBase : CallbackBase, IMicroComExceptionCallback
+    internal abstract class NativeCallbackBase : CallbackBase, IMicroComExceptionCallback
     {
         public void RaiseException(Exception e)
         {
diff --git a/src/Avalonia.Native/MacOSMountedVolumeInfoProvider.cs b/src/Avalonia.Native/MacOSMountedVolumeInfoProvider.cs
index e79c7a40d3..1170a6fd9b 100644
--- a/src/Avalonia.Native/MacOSMountedVolumeInfoProvider.cs
+++ b/src/Avalonia.Native/MacOSMountedVolumeInfoProvider.cs
@@ -64,7 +64,7 @@ namespace Avalonia.Native
         }
     }
 
-    public class MacOSMountedVolumeInfoProvider : IMountedVolumeInfoProvider
+    internal class MacOSMountedVolumeInfoProvider : IMountedVolumeInfoProvider
     {
         public IDisposable Listen(ObservableCollection<MountedVolumeInfo> mountedDrives)
         {
diff --git a/src/Avalonia.Native/MenuActionCallback.cs b/src/Avalonia.Native/MenuActionCallback.cs
index 3acbb9c19c..e9446e2da1 100644
--- a/src/Avalonia.Native/MenuActionCallback.cs
+++ b/src/Avalonia.Native/MenuActionCallback.cs
@@ -3,7 +3,7 @@ using Avalonia.Native.Interop;
 
 namespace Avalonia.Native
 {
-    public class MenuActionCallback : NativeCallbackBase, IAvnActionCallback
+    internal class MenuActionCallback : NativeCallbackBase, IAvnActionCallback
     {
         private Action _action;
 
diff --git a/src/Avalonia.Native/PredicateCallback.cs b/src/Avalonia.Native/PredicateCallback.cs
index dbb65791f0..1ff71063af 100644
--- a/src/Avalonia.Native/PredicateCallback.cs
+++ b/src/Avalonia.Native/PredicateCallback.cs
@@ -3,7 +3,7 @@ using Avalonia.Native.Interop;
 
 namespace Avalonia.Native
 {
-    public class PredicateCallback : NativeCallbackBase, IAvnPredicateCallback
+    internal class PredicateCallback : NativeCallbackBase, IAvnPredicateCallback
     {
         private Func<bool> _predicate;
 
diff --git a/src/Avalonia.Native/ScreenImpl.cs b/src/Avalonia.Native/ScreenImpl.cs
index 53bd12cde1..c64d1378e8 100644
--- a/src/Avalonia.Native/ScreenImpl.cs
+++ b/src/Avalonia.Native/ScreenImpl.cs
@@ -5,7 +5,7 @@ using Avalonia.Platform;
 
 namespace Avalonia.Native
 {
-    class ScreenImpl : IScreenImpl, IDisposable
+    internal class ScreenImpl : IScreenImpl, IDisposable
     {
         private IAvnScreens _native;
 
diff --git a/src/iOS/Avalonia.iOS/ClipboardImpl.cs b/src/iOS/Avalonia.iOS/ClipboardImpl.cs
index b9f74d69c6..150f3424e3 100644
--- a/src/iOS/Avalonia.iOS/ClipboardImpl.cs
+++ b/src/iOS/Avalonia.iOS/ClipboardImpl.cs
@@ -6,7 +6,7 @@ using UIKit;
 
 namespace Avalonia.iOS
 {
-    public class ClipboardImpl : IClipboard
+    internal class ClipboardImpl : IClipboard
     {
         public Task<string> GetTextAsync()
         {
@@ -16,19 +16,19 @@ namespace Avalonia.iOS
         public Task SetTextAsync(string text)
         {
             UIPasteboard.General.String = text;
-            return Task.FromResult(0);
+            return Task.CompletedTask;
         }
 
         public Task ClearAsync()
         {
             UIPasteboard.General.String = "";
-            return Task.FromResult(0);
+            return Task.CompletedTask;
         }
 
-        public Task SetDataObjectAsync(IDataObject data) => throw new PlatformNotSupportedException();
+        public Task SetDataObjectAsync(IDataObject data) => Task.CompletedTask;
 
-        public Task<string[]> GetFormatsAsync() => throw new PlatformNotSupportedException();
+        public Task<string[]> GetFormatsAsync() => Task.FromResult(Array.Empty<string>());
 
-        public Task<object> GetDataAsync(string format) => throw new PlatformNotSupportedException();
+        public Task<object> GetDataAsync(string format) => Task.FromResult<object>(null);
     }
-}
\ No newline at end of file
+}
diff --git a/src/iOS/Avalonia.iOS/LayerFbo.cs b/src/iOS/Avalonia.iOS/LayerFbo.cs
index 9a93cdfb22..c19fb2ee8d 100644
--- a/src/iOS/Avalonia.iOS/LayerFbo.cs
+++ b/src/iOS/Avalonia.iOS/LayerFbo.cs
@@ -5,7 +5,7 @@ using OpenGLES;
 
 namespace Avalonia.iOS
 {
-    public class LayerFbo
+    internal class LayerFbo
     {
         private readonly EAGLContext _context;
         private readonly GlInterface _gl;
diff --git a/src/iOS/Avalonia.iOS/Stubs.cs b/src/iOS/Avalonia.iOS/Stubs.cs
index 9c46aa78cc..6ac89fcab2 100644
--- a/src/iOS/Avalonia.iOS/Stubs.cs
+++ b/src/iOS/Avalonia.iOS/Stubs.cs
@@ -5,7 +5,7 @@ using Avalonia.Platform;
 
 namespace Avalonia.iOS
 {
-    class CursorFactoryStub : ICursorFactory
+    internal class CursorFactoryStub : ICursorFactory
     {
         public ICursorImpl CreateCursor(IBitmapImpl cursor, PixelPoint hotSpot) => new CursorImplStub();
         ICursorImpl ICursorFactory.GetCursor(StandardCursorType cursorType) => new CursorImplStub();
@@ -16,7 +16,7 @@ namespace Avalonia.iOS
         }
     }
 
-    class WindowingPlatformStub : IWindowingPlatform
+    internal class WindowingPlatformStub : IWindowingPlatform
     {
         public IWindowImpl CreateWindow() => throw new NotSupportedException();
 
@@ -25,7 +25,7 @@ namespace Avalonia.iOS
         public ITrayIconImpl CreateTrayIcon() => null;
     }
     
-    class PlatformIconLoaderStub : IPlatformIconLoader
+    internal class PlatformIconLoaderStub : IPlatformIconLoader
     {
         public IWindowIconImpl LoadIcon(IBitmapImpl bitmap)
         {
@@ -50,7 +50,7 @@ namespace Avalonia.iOS
         }
     }
 
-    public class IconStub : IWindowIconImpl
+    internal class IconStub : IWindowIconImpl
     {
         private readonly MemoryStream _ms;