diff --git a/example/main.ml b/example/main.ml
index abfe34a..5fbe7c4 100644
--- a/example/main.ml
+++ b/example/main.ml
@@ -4,7 +4,7 @@ let map = Leaflet.Map.create_on "map"
 (* setup map *)
 let () =
   (* set osm layer *)
-  let osm_layer = Leaflet.Layer.create_tile_osm [] in
+  let osm_layer = Leaflet.Layer.create_tile_osm [||] in
   Leaflet.Layer.add_to map osm_layer;
 
   (* set view *)
diff --git a/src/icon.ml b/src/icon.ml
index 4ed4972..d59a69f 100644
--- a/src/icon.ml
+++ b/src/icon.ml
@@ -46,12 +46,12 @@ let opt_to_jv = function
     match o with Some s -> Jv.of_string s | None -> Jv.of_bool false )
 
 let create icon_url options =
-  let l = List.map (fun o -> (to_string o, opt_to_jv o)) options in
-  let l = Array.of_list @@ (("iconUrl", Jv.of_string icon_url) :: l) in
+  let l = Array.map (fun o -> (to_string o, opt_to_jv o)) options in
+  let l = Array.append [| ("iconUrl", Jv.of_string icon_url) |] l in
   Jv.call Global.leaflet "icon" [| Jv.obj l |]
 
 let create_div ~html ~bg_pos options =
-  let l = List.map (fun o -> (to_string o, opt_to_jv o)) options in
+  let l = Array.map (fun o -> (to_string o, opt_to_jv o)) options in
   let div_options =
     let html =
       match html with
@@ -63,9 +63,9 @@ let create_div ~html ~bg_pos options =
       | None -> []
       | Some bg_pos -> [ ("bgPos", Point.to_jv bg_pos) ]
     in
-    html @ bg_pos
+    html @ bg_pos |> Array.of_list
   in
-  let l = Array.of_list @@ div_options @ l in
+  let l = Array.append div_options l in
   Jv.call Global.leaflet "divIcon" [| Jv.obj l |]
 
 let set_default_image_path s =
diff --git a/src/icon.mli b/src/icon.mli
index 451b51f..f490910 100644
--- a/src/icon.mli
+++ b/src/icon.mli
@@ -24,13 +24,13 @@ type opt =
 
 (** [create icon_url options] Creates an icon instance with the given [options],
     and the required `iconUrl` option set to [icon_url] *)
-val create : string -> opt list -> t
+val create : string -> opt array -> t
 
 (** [create_div ~html ~bg_pos options] Creates an DivIcon instance with the
     given [options], [bg_pos] is the optional relative position of the
     background, in pixels [html] is custom HTML code to put inside the div
     element, empty by default. *)
-val create_div : html:string option -> bg_pos:Point.t option -> opt list -> t
+val create_div : html:string option -> bg_pos:Point.t option -> opt array -> t
 
 (** Sets the path of the default icon *)
 val set_default_image_path : string -> unit
diff --git a/src/layer.ml b/src/layer.ml
index 12c35c3..e001331 100644
--- a/src/layer.ml
+++ b/src/layer.ml
@@ -110,13 +110,10 @@ let geojson_opt_to_jv = function
   | Filter f -> Jv.repr f
   | Coords_to_latlng f -> Jv.repr f
 
-let create_geojson : Jv.t -> geojson_opt list -> [ `Geojson ] t =
+let create_geojson : Jv.t -> geojson_opt array -> [ `Geojson ] t =
  fun geojson options ->
   let l =
-    Array.of_list
-    @@ List.map
-         (fun o -> (geojson_opt_to_string o, geojson_opt_to_jv o))
-         options
+    Array.map (fun o -> (geojson_opt_to_string o, geojson_opt_to_jv o)) options
   in
   let jv_t = Jv.call Global.leaflet "geoJSON" [| geojson; Jv.obj l |] in
   Geojson jv_t
@@ -205,21 +202,21 @@ let tile_layer_opt_to_jv = function
     Jv.call Global.leaflet "latLngBounds" [| Latlng.to_jv a; Latlng.to_jv b |]
 
 let create_tile :
-    string -> attribution:string -> tile_layer_opt list -> [ `Tile ] t =
+    string -> attribution:string -> tile_layer_opt array -> [ `Tile ] t =
  fun url ~attribution options ->
   let arr =
-    Array.of_list
-    @@ ("attribution", Jv.of_string attribution)
-       :: List.map
-            (fun o -> (tile_layer_opt_to_string o, tile_layer_opt_to_jv o))
-            options
+    Array.append
+      [| ("attribution", Jv.of_string attribution) |]
+      (Array.map
+         (fun o -> (tile_layer_opt_to_string o, tile_layer_opt_to_jv o))
+         options )
   in
   let jv_t =
     Jv.call Global.leaflet "tileLayer" [| Jv.of_string url; Jv.obj arr |]
   in
   Tile jv_t
 
-let create_tile_osm : tile_layer_opt list -> [ `Tile ] t =
+let create_tile_osm : tile_layer_opt array -> [ `Tile ] t =
  fun options ->
   let url = "https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png" in
   let attribution =
@@ -231,8 +228,8 @@ let create_tile_osm : tile_layer_opt list -> [ `Tile ] t =
 
 (* Vector Layers *)
 
-let create_polyline : Latlng.t list -> [ `Vector ] t =
+let create_polyline : Latlng.t array -> [ `Vector ] t =
  fun l ->
-  let l = Jv.of_list Latlng.to_jv l in
+  let l = Jv.of_array Latlng.to_jv l in
   let jv_t = Jv.call Global.leaflet "polyline" [| l |] in
   Vector jv_t
diff --git a/src/layer.mli b/src/layer.mli
index 1f34363..170ceb9 100644
--- a/src/layer.mli
+++ b/src/layer.mli
@@ -62,7 +62,7 @@ type geojson_opt =
   | Markers_inherit_options of bool
 
 (** [create_geojson geojson] is a new geojson layer *)
-val create_geojson : Jv.t -> geojson_opt list -> [ `Geojson ] t
+val create_geojson : Jv.t -> geojson_opt array -> [ `Geojson ] t
 
 (** Tile layers *)
 
@@ -93,12 +93,12 @@ type tile_layer_opt =
 
 (** [create_tile url attribution opts] create a new tile layer *)
 val create_tile :
-  string -> attribution:string -> tile_layer_opt list -> [ `Tile ] t
+  string -> attribution:string -> tile_layer_opt array -> [ `Tile ] t
 
 (** [create_tile_osm opts] create a new tile layer with tile server and
     attribution set to [openstreetmap.org]. See
     {:https://wiki.openstreetmap.org/wiki/Tile_servers} *)
-val create_tile_osm : tile_layer_opt list -> [ `Tile ] t
+val create_tile_osm : tile_layer_opt array -> [ `Tile ] t
 
 (** [create_polyline l] create a polyline layer from [l] *)
-val create_polyline : Latlng.t list -> [ `Vector ] t
+val create_polyline : Latlng.t array -> [ `Vector ] t
diff --git a/src/marker.ml b/src/marker.ml
index 93ebd05..7bf5f14 100644
--- a/src/marker.ml
+++ b/src/marker.ml
@@ -40,11 +40,9 @@ let opt_to_jv = function
   | Z_index_offset i | Rise_offset i -> Jv.of_int i
   | Opacity f -> Jv.of_float f
 
-let create : Latlng.t -> opt list -> t =
+let create : Latlng.t -> opt array -> t =
  fun latlng options ->
-  let l =
-    Array.of_list @@ List.map (fun o -> (opt_to_string o, opt_to_jv o)) options
-  in
+  let l = Array.map (fun o -> (opt_to_string o, opt_to_jv o)) options in
   let jv_t =
     Jv.call Global.leaflet "marker" [| Latlng.to_jv latlng; Jv.obj l |]
   in
diff --git a/src/marker.mli b/src/marker.mli
index ebb8096..a8c1237 100644
--- a/src/marker.mli
+++ b/src/marker.mli
@@ -17,7 +17,7 @@ type opt =
 
 (** [create latlng options] is a new marker with the same position as [latlng]
     and with options set to [options] *)
-val create : Latlng.t -> opt list -> t
+val create : Latlng.t -> opt array -> t
 
 (** Returns the current geographical position of the marker. *)
 val get_latlng : t -> Latlng.t
diff --git a/src/popup.ml b/src/popup.ml
index 3960a81..d3c077a 100644
--- a/src/popup.ml
+++ b/src/popup.ml
@@ -69,9 +69,7 @@ let opt_to_jv = function
   | Pane s | Class_name s -> Jv.of_string s
 
 let create ~content ~latlng options =
-  let l =
-    Array.of_list @@ List.map (fun o -> (opt_to_string o, opt_to_jv o)) options
-  in
+  let l = Array.map (fun o -> (opt_to_string o, opt_to_jv o)) options in
   let popup = Jv.call Global.leaflet "popup" [| Jv.obj l |] in
   let popup =
     match latlng with
@@ -87,9 +85,7 @@ let create ~content ~latlng options =
     popup
 
 let create_from_el el ~latlng options =
-  let l =
-    Array.of_list @@ List.map (fun o -> (opt_to_string o, opt_to_jv o)) options
-  in
+  let l = Array.map (fun o -> (opt_to_string o, opt_to_jv o)) options in
   let popup = Jv.call Global.leaflet "popup" [| Jv.obj l |] in
   let popup =
     match latlng with
diff --git a/src/popup.mli b/src/popup.mli
index d099745..f8dfc84 100644
--- a/src/popup.mli
+++ b/src/popup.mli
@@ -43,8 +43,8 @@ val opt_to_jv : opt -> Jv.t
 
 (** [create ~content ~latlng options] is a new popup setup with [options],
     position set to [latlng] and content to [s] *)
-val create : content:string option -> latlng:Latlng.t option -> opt list -> t
+val create : content:string option -> latlng:Latlng.t option -> opt array -> t
 
 (** [create_from_el el latlng options] is a new popup setup with [options],
     position set to [latlng] and content to [el] *)
-val create_from_el : Brr.El.t -> latlng:Latlng.t option -> opt list -> t
+val create_from_el : Brr.El.t -> latlng:Latlng.t option -> opt array -> t