diff --git a/src/WpfMath.Tests/GeometryElementRendererTests.fs b/src/WpfMath.Tests/GeometryElementRendererTests.fs
index a35b5285..0eea06a9 100644
--- a/src/WpfMath.Tests/GeometryElementRendererTests.fs
+++ b/src/WpfMath.Tests/GeometryElementRendererTests.fs
@@ -29,7 +29,7 @@ type GeometryElementRendererTests() =
         let font = DefaultTexFont(WpfMathFontProvider.Instance, 20.0)
         let environment = TexEnvironment(TexStyle.Display, font, font)
         let char = environment.MathFont.GetDefaultCharInfo('x', TexStyle.Display).Value
-        renderer.RenderCharacter(char, 0.0, 0.0, WpfBrushExtensions.ToPlatform Brushes.Black)
+        renderer.RenderCharacter(char, 0.0, 0.0, WpfExtensions.ToPlatform Brushes.Black)
 
         let group = Seq.exactlyOne geometry.Children :?> GeometryGroup
         Assert.IsType<PathGeometry>(Seq.exactlyOne group.Children) |> ignore