diff --git a/src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs b/src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs
index a2bdcd1ea8c..18348571bf6 100644
--- a/src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs
+++ b/src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs
@@ -101,7 +101,7 @@ public virtual void Detach(IMenu menu)
                 root.Deactivated -= WindowDeactivated;
             }
             
-            if (_root is TopLevel tl)
+            if (_root is TopLevel tl && tl.PlatformImpl != null)
                 tl.PlatformImpl.LostFocus -= TopLevelLostPlatformFocus;
 
             _inputManagerSubscription?.Dispose();