diff --git a/src/Wpf.Ui/UiApplication.cs b/src/Wpf.Ui/UiApplication.cs
index 43b1e92f2..37f4c5a4f 100644
--- a/src/Wpf.Ui/UiApplication.cs
+++ b/src/Wpf.Ui/UiApplication.cs
@@ -10,6 +10,7 @@ namespace Wpf.Ui;
 /// </summary>
 public class UiApplication
 {
+    [ThreadStatic]
     private static UiApplication? _uiApplication;
 
     private readonly Application? _application;