diff --git a/samples/ControlCatalog.Desktop/Program.cs b/samples/ControlCatalog.Desktop/Program.cs
index 2bfd223bb6..b7aa34f5ba 100644
--- a/samples/ControlCatalog.Desktop/Program.cs
+++ b/samples/ControlCatalog.Desktop/Program.cs
@@ -16,12 +16,7 @@ namespace ControlCatalog
         {
             // TODO: Make this work with GTK/Skia/Cairo depending on command-line args
             // again.
-            BuildAvaloniaApp().Start(AppMain, args);
-        }
-
-        private static void AppMain(Application app, string[] args)
-        {
-            app.Run();
+            BuildAvaloniaApp().Start<MainWindow>();
         }
 
         /// <summary>
diff --git a/samples/ControlCatalog.NetCore/Program.cs b/samples/ControlCatalog.NetCore/Program.cs
index 6a8175129f..c8f3fb9921 100644
--- a/samples/ControlCatalog.NetCore/Program.cs
+++ b/samples/ControlCatalog.NetCore/Program.cs
@@ -9,7 +9,8 @@ using Avalonia.ReactiveUI;
 namespace ControlCatalog.NetCore
 {
     static class Program
-    {       
+    {
+
         static void Main(string[] args)
         {
             Thread.CurrentThread.TrySetApartmentState(ApartmentState.STA);
@@ -28,10 +29,15 @@ namespace ControlCatalog.NetCore
                 AppBuilder.Configure<App>().InitializeWithLinuxFramebuffer(tl =>
                 {
                     tl.Content = new MainView();
-                    ThreadPool.QueueUserWorkItem(_ => ConsoleSilencer());
+                    System.Threading.ThreadPool.QueueUserWorkItem(_ => ConsoleSilencer());
                 });
             else
-                BuildAvaloniaApp().Start<MainWindow>();
+                BuildAvaloniaApp().Start(AppMain, args);
+        }
+
+        static void AppMain(Application app, string[] args)
+        {
+            app.Run(new MainWindow());
         }
 
         /// <summary>
diff --git a/samples/Previewer/App.xaml.cs b/samples/Previewer/App.xaml.cs
index 6d7d051218..4c18874b04 100644
--- a/samples/Previewer/App.xaml.cs
+++ b/samples/Previewer/App.xaml.cs
@@ -1,5 +1,4 @@
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
 namespace Previewer
diff --git a/samples/RenderDemo/App.xaml.cs b/samples/RenderDemo/App.xaml.cs
index ce75a335d5..d95018520a 100644
--- a/samples/RenderDemo/App.xaml.cs
+++ b/samples/RenderDemo/App.xaml.cs
@@ -2,7 +2,6 @@
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Logging.Serilog;
 using Avalonia.Markup.Xaml;
 using Avalonia.ReactiveUI;
diff --git a/samples/VirtualizationDemo/App.xaml.cs b/samples/VirtualizationDemo/App.xaml.cs
index 637c8726f6..b220807443 100644
--- a/samples/VirtualizationDemo/App.xaml.cs
+++ b/samples/VirtualizationDemo/App.xaml.cs
@@ -2,7 +2,6 @@
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
 namespace VirtualizationDemo
diff --git a/samples/interop/Direct3DInteropSample/App.paml.cs b/samples/interop/Direct3DInteropSample/App.paml.cs
index 5269854138..1b6d5fd39c 100644
--- a/samples/interop/Direct3DInteropSample/App.paml.cs
+++ b/samples/interop/Direct3DInteropSample/App.paml.cs
@@ -1,5 +1,4 @@
 using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
 namespace Direct3DInteropSample
diff --git a/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs b/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs
index caa3c1baa8..5ee3487b6b 100644
--- a/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs
+++ b/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs
@@ -1,11 +1,10 @@
-using Avalonia.Controls;
-using Avalonia.Markup.Xaml;
+using Avalonia.Markup.Xaml;
 
 namespace Avalonia.DesignerSupport.TestApp
 {
     public class App : Application
     {
-        public override void Initialize()                         
+        public override void Initialize()
         {
             AvaloniaXamlLoader.Load(this);
         }