diff --git a/squirrelbattle/mapgeneration/broguelike.py b/squirrelbattle/mapgeneration/broguelike.py
index 72f773c..d6da979 100644
--- a/squirrelbattle/mapgeneration/broguelike.py
+++ b/squirrelbattle/mapgeneration/broguelike.py
@@ -29,15 +29,17 @@ class Generator:
 
     @staticmethod
     def room_fits(level, y, x, room, door_y, door_x, dy, dx):
-        if level[y][x] != Tile.EMPTY or level[y-dy][x-dx] != Tile.FLOOR:
-            return False
         lh, lw = len(level), len(level[0])
         rh, rw = len(room), len(room[0])
+        if not(0 < y+dy < lh and 0 < x+dx < lw):
+            return False
+        if level[y][x] != Tile.EMPTY or level[y+dy][x+dx] != Tile.FLOOR:
+            return False
         for ry in range(rh):
             for rx in range(rw):
                 if room[ry][rx] == Tile.FLOOR:
                     ly, lx = y + ry - door_y, x + rx - door_x
-                    if not(0 <= ly <= rh and 0 <= lx <= rw) or \
+                    if not(0 <= ly < lh and 0 <= lx < lw) or \
                             level[ly][lx] == Tile.FLOOR:
                         return False
         return True