diff --git a/frontend/src/Main.elm b/frontend/src/Main.elm
index 0324b3d..e7aa545 100644
--- a/frontend/src/Main.elm
+++ b/frontend/src/Main.elm
@@ -216,10 +216,10 @@ tileImg zoom tilenumber = img [ width 256,
                                 height 256,
                                 src (tileUrl tilenumber zoom) ] []
 
-trackView : List Point -> Int -> Int -> Svg Msg
-trackView points leftedge topedge =
+trackView : List Point -> Int -> Int -> Zoom -> Svg Msg
+trackView points leftedge topedge zoom =
     let plot p =
-            let (x, y) = pixelFromCoord (toCoord p.pos.lat p.pos.lon) 13
+            let (x, y) = pixelFromCoord (toCoord p.pos.lat p.pos.lon) zoom
                 x_ = x - leftedge
                 y_ = y - topedge
             in (String.fromInt x_) ++ ", " ++
@@ -269,7 +269,7 @@ canvas centre zoom width height track =
         ys = List.range mintile.y maxtile.y
         epos e = Tuple.mapBoth floor floor e.pointer.clientPos
         tv = case track of
-                 Present t -> trackView t leftedge topedge
+                 Present t -> trackView t leftedge topedge zoom
                  Failure f -> Debug.log f (div [] [ text "failure", text f])
                  Loading -> div [] [text "loading"]
                  Empty -> div [] [text "no points"]