diff --git a/src/Avalonia.Controls/AppBuilderBase.cs b/src/Avalonia.Controls/AppBuilderBase.cs
index 967ebac4ef..0f0b55e9e8 100644
--- a/src/Avalonia.Controls/AppBuilderBase.cs
+++ b/src/Avalonia.Controls/AppBuilderBase.cs
@@ -57,10 +57,6 @@ namespace Avalonia.Controls
         /// </summary>
         public Action<TAppBuilder> AfterSetupCallback { get; private set; } = builder => { };
 
-        /// <summary>
-        /// Gets or sets a method to call before Start is called on the <see cref="Application"/>.
-        /// </summary>
-        public Action<TAppBuilder> BeforeStartCallback { get; private set; } = builder => { };
 
         protected AppBuilderBase(IRuntimePlatform platform, Action<TAppBuilder> platformServices)
         {
@@ -95,17 +91,6 @@ namespace Avalonia.Controls
 
         protected TAppBuilder Self => (TAppBuilder)this;
 
-        /// <summary>
-        /// Registers a callback to call before Start is called on the <see cref="Application"/>.
-        /// </summary>
-        /// <param name="callback">The callback.</param>
-        /// <returns>An <typeparamref name="TAppBuilder"/> instance.</returns>
-        public TAppBuilder BeforeStarting(Action<TAppBuilder> callback)
-        {
-            BeforeStartCallback = (Action<TAppBuilder>)Delegate.Combine(BeforeStartCallback, callback);
-            return Self;
-        }
-
         public TAppBuilder AfterSetup(Action<TAppBuilder> callback)
         {
             AfterSetupCallback = (Action<TAppBuilder>)Delegate.Combine(AfterSetupCallback, callback);
@@ -121,47 +106,24 @@ namespace Avalonia.Controls
         public void Start<TMainWindow>(Func<object> dataContextProvider = null)
             where TMainWindow : Window, new()
         {
-            Setup();
-            BeforeStartCallback(Self);
-
             var window = new TMainWindow();
             if (dataContextProvider != null)
                 window.DataContext = dataContextProvider();
             Instance.Run(window);
         }
 
-        /// <summary>
-        /// Starts the application with the provided instance of <typeparamref name="TMainWindow"/>.
-        /// </summary>
-        /// <typeparam name="TMainWindow">The window type.</typeparam>
-        /// <param name="mainWindow">Instance of type TMainWindow to use when starting the app</param>
-        /// <param name="dataContextProvider">A delegate that will be called to create a data context for the window (optional).</param>
-        [Obsolete("Use either lifetimes or AppMain overload. See see https://github.com/AvaloniaUI/Avalonia/wiki/Application-lifetimes for details")]
-        public void Start<TMainWindow>(TMainWindow mainWindow, Func<object> dataContextProvider = null)
-            where TMainWindow : Window
-        {
-            Setup();
-            BeforeStartCallback(Self);
-
-            if (dataContextProvider != null)
-                mainWindow.DataContext = dataContextProvider();
-            Instance.Run(mainWindow);
-        }
-
         public delegate void AppMainDelegate(Application app, string[] args);
 
         [Obsolete("Use either lifetimes or AppMain overload. See see https://github.com/AvaloniaUI/Avalonia/wiki/Application-lifetimes for details")]
         public void Start()
         {
             Setup();
-            BeforeStartCallback(Self);
             Instance.Run();
         }
 
         public void Start(AppMainDelegate main, string[] args)
         {
             Setup();
-            BeforeStartCallback(Self);
             main(Instance, args);
         }