diff --git a/src/Markup/Avalonia.Markup/Data/Plugins/AvaloniaPropertyAccessorPlugin.cs b/src/Markup/Avalonia.Markup/Data/Plugins/AvaloniaPropertyAccessorPlugin.cs
index 3f6f15ed5b..90eabc69fb 100644
--- a/src/Markup/Avalonia.Markup/Data/Plugins/AvaloniaPropertyAccessorPlugin.cs
+++ b/src/Markup/Avalonia.Markup/Data/Plugins/AvaloniaPropertyAccessorPlugin.cs
@@ -104,7 +104,7 @@ namespace Avalonia.Markup.Data.Plugins
 
             protected override void SubscribeCore(IObserver<object> observer)
             {
-                _subscription = Instance.GetWeakObservable(_property).Subscribe(observer);
+                _subscription = Instance?.GetWeakObservable(_property).Subscribe(observer);
             }
         }
     }