diff --git a/src/Hypercube.Core/Graphics/Utilities/Extensions/SilkGLExtension.cs b/src/Hypercube.Core/Graphics/Utilities/Extensions/SilkGLExtension.cs
index d9a6702..75b04e1 100644
--- a/src/Hypercube.Core/Graphics/Utilities/Extensions/SilkGLExtension.cs
+++ b/src/Hypercube.Core/Graphics/Utilities/Extensions/SilkGLExtension.cs
@@ -42,7 +42,7 @@ public void SetScissor(bool value)
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Viewport(IWindow window)
         {
-            gl.Viewport(window.Size);
+            gl.Viewport(window.FramebufferSize);
         }
 
         [PublicAPI]