diff --git a/src/Avalonia.Native/AvaloniaNativeDeferredRendererLock.cs b/src/Avalonia.Native/AvaloniaNativeDeferredRendererLock.cs
index 0031cc5b03..ce2b03e355 100644
--- a/src/Avalonia.Native/AvaloniaNativeDeferredRendererLock.cs
+++ b/src/Avalonia.Native/AvaloniaNativeDeferredRendererLock.cs
@@ -24,7 +24,7 @@ namespace Avalonia.Native
             return null;
         }
 
-        private class UnlockDisposable : IDisposable
+        private sealed class UnlockDisposable : IDisposable
         {
             private IAvnWindowBase _window;
 
diff --git a/src/Avalonia.Visuals/Rendering/ManagedDeferredRendererLock.cs b/src/Avalonia.Visuals/Rendering/ManagedDeferredRendererLock.cs
index a87fc9e39f..259874423e 100644
--- a/src/Avalonia.Visuals/Rendering/ManagedDeferredRendererLock.cs
+++ b/src/Avalonia.Visuals/Rendering/ManagedDeferredRendererLock.cs
@@ -30,7 +30,7 @@ namespace Avalonia.Rendering
             return new UnlockDisposable(_lock);
         }
 
-        private class UnlockDisposable : IDisposable
+        private sealed class UnlockDisposable : IDisposable
         {
             private object _lock;