diff --git a/samples/BindingTest/App.xaml.cs b/samples/BindingTest/App.xaml.cs
index 07fa406c1c..fd457f7ba9 100644
--- a/samples/BindingTest/App.xaml.cs
+++ b/samples/BindingTest/App.xaml.cs
@@ -9,11 +9,6 @@ namespace BindingTest
 {
     public class App : Application
     {
-        public App()
-        {
-            RegisterServices();
-        }
-
         public override void Initialize()
         {
             AvaloniaXamlLoader.Load(this);
diff --git a/samples/ControlCatalog/App.xaml.cs b/samples/ControlCatalog/App.xaml.cs
index fe2ccdb218..d862749132 100644
--- a/samples/ControlCatalog/App.xaml.cs
+++ b/samples/ControlCatalog/App.xaml.cs
@@ -5,11 +5,6 @@ namespace ControlCatalog
 {
     public class App : Application
     {
-        public App()
-        {
-            RegisterServices();
-        }
-
         public override void Initialize()
         {
             AvaloniaXamlLoader.Load(this);
diff --git a/samples/TestApplicationShared/App.cs b/samples/TestApplicationShared/App.cs
index b7e80bb41e..757ecc72bb 100644
--- a/samples/TestApplicationShared/App.cs
+++ b/samples/TestApplicationShared/App.cs
@@ -17,15 +17,6 @@ namespace TestApplication
 {
     public class App : Application
     {
-        public App()
-        {
-            // TODO: I believe this has to happen before we select sub systems. Can we
-            // move this safely into Application itself? Is there anything in here
-            // that is platform specific??
-            //
-            RegisterServices();
-        }
-
         public void Run()
         {
             Styles.Add(new DefaultTheme());
diff --git a/samples/XamlTestApplicationPcl/XamlTestApp.cs b/samples/XamlTestApplicationPcl/XamlTestApp.cs
index 7518346e91..dbdf8f2ad2 100644
--- a/samples/XamlTestApplicationPcl/XamlTestApp.cs
+++ b/samples/XamlTestApplicationPcl/XamlTestApp.cs
@@ -6,11 +6,6 @@ namespace XamlTestApplication
 {
     public class XamlTestApp : Application
     {
-        public XamlTestApp()
-        {
-            RegisterServices();
-        }
-
         public override void Initialize()
         {
             AvaloniaXamlLoader.Load(this);
diff --git a/src/Avalonia.Controls/AppBuilder.cs b/src/Avalonia.Controls/AppBuilder.cs
index 428b823dac..df50a105be 100644
--- a/src/Avalonia.Controls/AppBuilder.cs
+++ b/src/Avalonia.Controls/AppBuilder.cs
@@ -83,7 +83,7 @@ namespace Avalonia.Controls
             {
                 throw new InvalidOperationException("No rendering system configured.");
             }
-
+            Instance.RegisterServices();
             WindowingSubsystem();
             RenderingSubsystem();
             Instance.Initialize();
diff --git a/src/Avalonia.Controls/Application.cs b/src/Avalonia.Controls/Application.cs
index aedf3370a3..f73ead5576 100644
--- a/src/Avalonia.Controls/Application.cs
+++ b/src/Avalonia.Controls/Application.cs
@@ -171,7 +171,7 @@ namespace Avalonia
         /// <summary>
         /// Register's the services needed by Avalonia.
         /// </summary>
-        protected virtual void RegisterServices()
+        public virtual void RegisterServices()
         {
             AvaloniaSynchronizationContext.InstallIfNeeded();
             FocusManager = new FocusManager();
diff --git a/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs b/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs
index f9407a4708..653a51232b 100644
--- a/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs
+++ b/tests/Avalonia.DesignerSupport.TestApp/App.xaml.cs
@@ -9,12 +9,6 @@ namespace Avalonia.DesignerSupport.TestApp
 {
     public class App : Application
     {
-
-        public App()
-        {
-            RegisterServices();
-        }
-
         public override void Initialize()
         {
             AvaloniaXamlLoader.Load(this);
diff --git a/tests/Avalonia.UnitTests/UnitTestApplication.cs b/tests/Avalonia.UnitTests/UnitTestApplication.cs
index 01151b4952..83c8a2cebc 100644
--- a/tests/Avalonia.UnitTests/UnitTestApplication.cs
+++ b/tests/Avalonia.UnitTests/UnitTestApplication.cs
@@ -12,22 +12,17 @@ namespace Avalonia.UnitTests
 {
     public class UnitTestApplication : Application
     {
+        private readonly TestServices _services;
+
         public UnitTestApplication(TestServices services)
         {
-            Services = services ?? new TestServices();
+            _services = services ?? new TestServices();
             RegisterServices();
-
-            var styles = Services.Theme?.Invoke();
-
-            if (styles != null)
-            {
-                Styles.AddRange(styles);
-            }
         }
 
         public static new UnitTestApplication Current => (UnitTestApplication)Application.Current;
 
-        public TestServices Services { get; }
+        public TestServices Services => _services;
 
         public static IDisposable Start(TestServices services = null)
         {
@@ -37,7 +32,7 @@ namespace Avalonia.UnitTests
             return scope;
         }
 
-        protected override void RegisterServices()
+        public override void RegisterServices()
         {
             AvaloniaLocator.CurrentMutable
                 .Bind<IAssetLoader>().ToConstant(Services.AssetLoader)
@@ -53,6 +48,12 @@ namespace Avalonia.UnitTests
                 .Bind<IStyler>().ToConstant(Services.Styler)
                 .Bind<IWindowingPlatform>().ToConstant(Services.WindowingPlatform)
                 .Bind<IApplicationLifecycle>().ToConstant(this);
+            var styles = Services.Theme?.Invoke();
+
+            if (styles != null)
+            {
+                Styles.AddRange(styles);
+            }
         }
     }
 }