diff --git a/squirrelbattle/mapgeneration/randomwalk.py b/squirrelbattle/mapgeneration/randomwalk.py
index bd3a20d..b3287ea 100644
--- a/squirrelbattle/mapgeneration/randomwalk.py
+++ b/squirrelbattle/mapgeneration/randomwalk.py
@@ -108,7 +108,7 @@ class Generator:
         for x in range(width):
             for y in range(height):
                 if grid[y][x] == Tile.EMPTY:
-                    c = sum([1 if grid[j][i] == Tile.FLOOR else 0 for j, i in result.neighbourhood(y, x, large=True])
+                    c = sum([1 if grid[j][i] == Tile.FLOOR else 0 for j, i in result.neighbourhood(y, x, large=True)])
                     if c == 4 and self.params["no_lone_walls"]:
                         result.tiles[y][x] = Tile.FLOOR
                     elif c > 0: