diff --git a/MapControl/MatrixEx.WPF.cs b/MapControl/MatrixEx.WPF.cs
index 2fbde59a..16477ee2 100644
--- a/MapControl/MatrixEx.WPF.cs
+++ b/MapControl/MatrixEx.WPF.cs
@@ -9,7 +9,7 @@ namespace MapControl
     internal static class MatrixEx
     {
         /// <summary>
-        /// Used in MapProjection.
+        /// Used in MapProjection and MapTileLayer.
         /// </summary>
         public static Matrix TranslateScaleRotateTranslate(
             double translation1X, double translation1Y,