diff --git a/public/tile-map.png b/public/tile-map.png
index 4695ed8..d006103 100644
Binary files a/public/tile-map.png and b/public/tile-map.png differ
diff --git a/renderer/Background.ts b/renderer/Background.ts
index 6cb885f..16f5342 100644
--- a/renderer/Background.ts
+++ b/renderer/Background.ts
@@ -70,7 +70,7 @@ export function getBitMask(
   map: string[][],
   x: number,
   y: number,
-  outOfBoundToken = " ",
+  outOfBoundToken = "R",
   cmp = (x: string) => x === "R",
 ) {
   const [topLeft, top, topRight, left, right, bottomLeft, bottom, bottomRight] =