diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/FoldingMargin.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/FoldingMargin.cs
index ad16aae88c..f2ee1b7947 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/FoldingMargin.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/FoldingMargin.cs
@@ -208,7 +208,7 @@ namespace ICSharpCode.AvalonEdit.Folding
 		/// </summary>
 		void DrawFoldLines(DrawingContext drawingContext, Pen[] colors, Pen[] endMarker)
 		{
-			double markerXPos = Math.Round(RenderSize.Width / 2);
+			double markerXPos = PixelSnapHelpers.PixelAlign(RenderSize.Width / 2);
 			double startY = 0;
 			Pen currentPen = colors[0];
 			int tlNumber = 0;
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/PixelSnapHelpers.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/PixelSnapHelpers.cs
index b5496528dc..1db689938c 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/PixelSnapHelpers.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/PixelSnapHelpers.cs
@@ -12,7 +12,7 @@ namespace ICSharpCode.AvalonEdit.Utils
 {
 	static class PixelSnapHelpers
 	{
-		static double PixelAlign(double val)
+		public static double PixelAlign(double val)
 		{
 			return Math.Round(val + 0.5) - 0.5;
 		}