diff --git a/ClosedXML/Extensions.cs b/ClosedXML/Extensions.cs
index 6cde6da..c2d1067 100644
--- a/ClosedXML/Extensions.cs
+++ b/ClosedXML/Extensions.cs
@@ -229,7 +229,7 @@
             var textSize = GraphicsUtils.MeasureString(text, font);
 
             double width = (((textSize.Width / (double)7) * 256) - (128 / 7)) / 256;
-            width = (double)decimal.Round((decimal)width + 0.2M, 2);
+            width = Math.Round(width + 0.2, 2);
 
             return width;
         }