diff --git a/PuzzlePlayer/Sudoku.cs b/PuzzlePlayer/Sudoku.cs
index e537c7f81f0bd604c2c519d8aaf2b20038957779..aeadcfe5fb12dc03cd395c762541dee4c202c4c6 100644
--- a/PuzzlePlayer/Sudoku.cs
+++ b/PuzzlePlayer/Sudoku.cs
@@ -69,6 +69,19 @@ namespace PuzzlePlayer_Namespace
                     }
                 }
             }
+            for (int i = 1; i < Math.Sqrt(boardState.GetLength(0)); i++)
+            {
+                gr.DrawLine(Pens.Black,
+                    r.X + i * (int)Math.Sqrt((double)boardState.GetLength(0)) * tilesize.Width,
+                    r.Y,
+                    r.X + i * (int)Math.Sqrt((double)boardState.GetLength(0)) * tilesize.Width,
+                    r.Bottom);
+                gr.DrawLine(Pens.Black,
+                    r.X,
+                    r.Y + i * (int)Math.Sqrt((double)boardState.GetLength(1)) * tilesize.Height,
+                    r.Right,
+                    r.Y + i * (int)Math.Sqrt((double)boardState.GetLength(1)) * tilesize.Height);
+            }
         }
 
         public override void Generate()