diff --git a/src/library/Uno.Themes.WinUI.Markup/Theme.LightWeight/Themes.LightWeightStyles.CheckBox.cs b/src/library/Uno.Themes.WinUI.Markup/Theme.LightWeight/Themes.LightWeightStyles.CheckBox.cs
index 7c81e972e..373c8fecc 100644
--- a/src/library/Uno.Themes.WinUI.Markup/Theme.LightWeight/Themes.LightWeightStyles.CheckBox.cs
+++ b/src/library/Uno.Themes.WinUI.Markup/Theme.LightWeight/Themes.LightWeightStyles.CheckBox.cs
@@ -1,5 +1,8 @@
-using System;
+#if WinUI
 using Microsoft.UI.Text;
+#else
+using Windows.UI.Text;
+#endif
 using Microsoft.UI.Xaml.Media;
 using Uno.Extensions.Markup.Internals;
 
@@ -173,10 +176,13 @@ public static class Typo
 					{
 						[ResourceKeyDefinition(typeof(FontFamily), "CheckBoxFontFamily")]
 						public static ResourceValue<FontFamily> FontFamily => new("CheckBoxFontFamily", true);
-
+#if WinUI
 						[ResourceKeyDefinition(typeof(FontWeights), "CheckBoxFontWeight")]
 						public static ResourceValue<FontWeights> FontWeight => new("CheckBoxFontWeight", true);
-
+#else
+						[ResourceKeyDefinition(typeof(FontWeight), "CheckBoxFontWeight")]
+						public static ResourceValue<FontWeight> FontWeight => new("CheckBoxFontWeight", true);
+#endif
 						[ResourceKeyDefinition(typeof(double), "CheckBoxFontSize")]
 						public static ResourceValue<double> FontSize => new("CheckBoxFontSize", true);