diff --git a/src/filter/bsp_interior.rs b/src/filter/bsp_interior.rs
index 8a7b504..7cc7f4c 100644
--- a/src/filter/bsp_interior.rs
+++ b/src/filter/bsp_interior.rs
@@ -130,12 +130,12 @@ mod tests {
         let gen = BspInterior::<NoData>::new();
         let map = gen.modify_map(&mut rng, &Map::new(80, 50));
         for i in 0..80 {
-            assert!(map.at(i, 0).is_blocked());
-            assert!(map.at(i, 49).is_blocked());
+            assert!(map.at(i, 0).unwrap().is_blocked());
+            assert!(map.at(i, 49).unwrap().is_blocked());
         }
         for j in 0..50 {
-            assert!(map.at(0, j).is_blocked());
-            assert!(map.at(79, j).is_blocked());
+            assert!(map.at(0, j).unwrap().is_blocked());
+            assert!(map.at(79, j).unwrap().is_blocked());
         }
     }
 }
diff --git a/src/filter/bsp_rooms.rs b/src/filter/bsp_rooms.rs
index 0fe4a8b..9c3da49 100644
--- a/src/filter/bsp_rooms.rs
+++ b/src/filter/bsp_rooms.rs
@@ -150,8 +150,12 @@ impl<D: Clone + Default> BspRooms<D> {
                 if y < 1 {
                     can_build = false;
                 }
-                if can_build && map.at(x as usize, y as usize).is_walkable() {
-                    can_build = false;
+                if can_build {
+                    if let Some(tile) = map.at(x as usize, y as usize) {
+                        if tile.is_walkable() {
+                            can_build = false;
+                        }
+                    }
                 }
             }
         }
@@ -174,12 +178,12 @@ mod tests {
         let gen = BspRooms::<NoData>::new();
         let map = gen.modify_map(&mut rng, &Map::new(80, 50));
         for i in 0..80 {
-            assert!(map.at(i, 0).is_blocked());
-            assert!(map.at(i, 49).is_blocked());
+            assert!(map.at(i, 0).unwrap().is_blocked());
+            assert!(map.at(i, 49).unwrap().is_blocked());
         }
         for j in 0..50 {
-            assert!(map.at(0, j).is_blocked());
-            assert!(map.at(79, j).is_blocked());
+            assert!(map.at(0, j).unwrap().is_blocked());
+            assert!(map.at(79, j).unwrap().is_blocked());
         }
     }
 }
diff --git a/src/filter/cellular_automata.rs b/src/filter/cellular_automata.rs
index 8526928..1722686 100644
--- a/src/filter/cellular_automata.rs
+++ b/src/filter/cellular_automata.rs
@@ -76,7 +76,7 @@ fn apply_iteration<D: Clone + Default>(map: &Map<D>) -> Map<D> {
             ];
             let neighbors = idxs
                 .iter()
-                .filter(|(x, y)| map.at(*x, *y).is_blocked())
+                .filter(|(x, y)| map.at(*x, *y).unwrap().is_blocked())
                 .count();
 
             if neighbors > 4 || neighbors == 0 {
@@ -103,7 +103,7 @@ mod tests {
     fn test_iteration_wal() {
         let map = Map::<NoData>::new(3, 3);
         let new_map = apply_iteration(&map);
-        assert!(new_map.at(1, 1).is_blocked());
+        assert!(new_map.at(1, 1).unwrap().is_blocked());
     }
 
     #[test]
@@ -115,6 +115,6 @@ mod tests {
             }
         }
         let new_map = apply_iteration(&map);
-        assert!(new_map.at(1, 1).is_walkable());
+        assert!(new_map.at(1, 1).unwrap().is_walkable());
     }
 }
diff --git a/src/map.rs b/src/map.rs
index 72d4d74..75b8f6d 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -112,13 +112,9 @@ impl<D: Clone + Default> Map<D> {
     }
 
     /// Get TileType at the given location
-    pub fn at(&self, x: usize, y: usize) -> Tile {
-        if x >= self.width || y >= self.height {
-            Tile::wall()
-        } else {
-            let idx = (y as usize) * self.width + (x as usize);
-            self.tiles[idx]
-        }
+    pub fn at(&self, x: usize, y: usize) -> Option<&Tile> {
+        let idx = (y as usize) * self.width + (x as usize);
+        self.tiles.get(idx)
     }
 
     /// Get available exists from the given tile
@@ -158,7 +154,11 @@ impl<D: Clone + Default> Map<D> {
 
     // Check if given tile can be accessed
     fn is_exit_valid(&self, x: usize, y: usize) -> bool {
-        !self.at(x, y).is_blocked
+        if let Some(tile) = self.at(x, y) {
+            !tile.is_blocked
+        } else {
+            false
+        }
     }
 
     /// Modify tile at the given location
@@ -200,9 +200,11 @@ impl<D: Clone + Default> Map<D> {
                 y -= 1;
             }
 
-            if self.at(x, y).is_blocked {
-                corridor.push(Point::new(x, y));
-                self.set_tile(x, y, Tile::floor());
+            if let Some(tile) = self.at(x, y) {
+                if tile.is_blocked {
+                    corridor.push(Point::new(x, y));
+                    self.set_tile(x, y, Tile::floor());
+                }
             }
         }
     }
@@ -274,7 +276,7 @@ impl<D: Clone + Default> fmt::Display for Map<D> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         for y in 0..self.height {
             let bytes: Vec<u8> = (0..self.width)
-                .map(|x| if self.at(x, y).is_blocked { '#' } else { ' ' } as u8)
+                .map(|x| if self.at(x, y).unwrap().is_blocked { '#' } else { ' ' } as u8)
                 .collect();
             let line = String::from_utf8(bytes).expect("Can't convert map to string");
             let _ = writeln!(f, "{}", line);
@@ -295,7 +297,7 @@ mod tests {
         let map = Map::<NoData>::new(10, 10);
         for i in 0..10 {
             for j in 0..10 {
-                assert!(map.at(i, j).is_blocked);
+                assert!(map.at(i, j).unwrap().is_blocked);
             }
         }
     }
@@ -312,12 +314,12 @@ mod tests {
         assert_eq!(map.width, 10);
         assert_eq!(map.height, 3);
         for i in 0..10 {
-            assert!(map.at(i, 0).is_blocked);
-            assert!(map.at(i, 2).is_blocked);
+            assert!(map.at(i, 0).unwrap().is_blocked);
+            assert!(map.at(i, 2).unwrap().is_blocked);
             if i == 0 || i == 9 {
-                assert!(map.at(i, 1).is_blocked);
+                assert!(map.at(i, 1).unwrap().is_blocked);
             } else {
-                assert!(map.at(i, 1).is_walkable());
+                assert!(map.at(i, 1).unwrap().is_walkable());
             }
         }
     }
@@ -343,9 +345,9 @@ mod tests {
         for x in 0..map.width {
             for y in 0..map.height {
                 if x == 0 || y == 0 || x == 4 || y == 4 {
-                    assert!(map.at(x, y).is_blocked);
+                    assert!(map.at(x, y).unwrap().is_blocked);
                 } else {
-                    assert!(map.at(x, y).is_walkable());
+                    assert!(map.at(x, y).unwrap().is_walkable());
                 }
             }
         }