diff --git a/packages/topdown/tiles.js b/packages/topdown/tiles.js
index e7e2409..60b86b3 100644
--- a/packages/topdown/tiles.js
+++ b/packages/topdown/tiles.js
@@ -58,12 +58,12 @@ export class Tiles extends decorate(class {}) {
     return Rectangle.compose([0, 0], this.size);
   }
 
-  setTileAt(x, y, tile) {
-    const oldTile = this.tileAt(x, y);
+  setTileAt(position, tile) {
+    const oldTile = this.tileAt(position);
     if (oldTile === tile) {
       return;
     }
-    const index = y * this.width + x;
+    const index = position[1] * this.width + position[0];
     if (index < 0 || index >= this.data.length) {
       return;
     }
@@ -99,8 +99,8 @@ export class Tiles extends decorate(class {}) {
     return slice;
   }
 
-  tileAt(x, y) {
-    return this.data[y * this.width + x];
+  tileAt(position) {
+    return this.data[position[1] * this.width + position[0]];
   }
 
   toJSON() {