     @_loadTile z, x, y
     .then (buffer) => @_unzipIfNeeded original = buffer
     .then (buffer) => @_decodeTile buffer
-    .then (tile) => @_callback tile
+    .then (tile) => @_callback tile, z, x, y
     .then (tile) => @_encodeTile tile
     .then (buffer) => @_gzip buffer
     .then (buffer) =>
       @_trackStats z, x, y, original, buffer
       @_storeTile z, x, y, buffer
 
-  _callback: (tile) ->
-    @callback tile
+  _callback: (tile, z, x, y) ->
+    @callback tile, z, x, y
     tile
 
   _storeTile: (z, x, y, buffer) ->

    @protobuf = new Protobuf fs.readFileSync __dirname+"/../proto/vector_tile.desc"

  grind: (source, @destination, @callback) ->
    @_log "[>] starting to grind"

    @_mustExist source
    .then => @_loadMBTiles source

  config:
    debug: true
    output: "mbtiles"
    maxZoom: 14

  queueSize: 64

