diff --git a/Toolkit.Foundation/IHostBuilderExtension.cs b/Toolkit.Foundation/IHostBuilderExtension.cs
index a73b20c..85afc5c 100644
--- a/Toolkit.Foundation/IHostBuilderExtension.cs
+++ b/Toolkit.Foundation/IHostBuilderExtension.cs
@@ -184,4 +184,17 @@ public static class IHostBuilderExtension
 
         return builder;
     }
+
+    public static IHostBuilder UseContentRoot(this IHostBuilder hostBuilder,
+                                        string contentRoot,
+        bool createDirectory)
+    {
+        if (createDirectory)
+        {
+            Directory.CreateDirectory(contentRoot);
+        }
+
+        hostBuilder.UseContentRoot(contentRoot);
+        return hostBuilder;
+    }
 }
\ No newline at end of file
diff --git a/Toolkit.Foundation/IHostBuilderExtensions.cs b/Toolkit.Foundation/IHostBuilderExtensions.cs
deleted file mode 100644
index bf3ed92..0000000
--- a/Toolkit.Foundation/IHostBuilderExtensions.cs
+++ /dev/null
@@ -1,19 +0,0 @@
-using Microsoft.Extensions.Hosting;
-
-namespace Toolkit.Foundation;
-
-public static class IHostBuilderExtensions
-{
-    public static IHostBuilder UseContentRoot(this IHostBuilder hostBuilder,
-        string contentRoot,
-        bool createDirectory)
-    {
-        if (createDirectory)
-        {
-            Directory.CreateDirectory(contentRoot);
-        }
-
-        hostBuilder.UseContentRoot(contentRoot);
-        return hostBuilder;
-    }
-}
\ No newline at end of file
diff --git a/Toolkit.UI.Controls.Avalonia/AppWindow/AppWindow.cs b/Toolkit.UI.Controls.Avalonia/AppWindow/AppWindow.cs
new file mode 100644
index 0000000..b9c369b
--- /dev/null
+++ b/Toolkit.UI.Controls.Avalonia/AppWindow/AppWindow.cs
@@ -0,0 +1,7 @@
+namespace Toolkit.UI.Controls.Avalonia;
+
+public class AppWindow : FluentAvalonia.UI.Windowing.AppWindow
+{
+    protected override Type StyleKeyOverride =>
+        typeof(FluentAvalonia.UI.Windowing.AppWindow);
+}
\ No newline at end of file