Haxe/cs convert interface to cs interface

I have a class like this

class Test_cs_interface {
    public var exits:List<MyPlaceable>;
    public function init(){
        exits=new List();
        exits.push(new Shelf());
    public function my_exits():List<MyPlaceable> {
        return exits;

interface MyPlaceable {
    public function place():Bool;

class Shelf implements MyPlaceable {
    public function new() {
    public function place():Bool{
        return true;

When compiling to CS haxe Test_cs_interface -cs testcs , the field exit becomes a List, this is causing me not to be able to cast it back to a cs MyPlaceable,

	public global::haxe.ds.List<object> exits;
	public virtual void init() {
		this.exits = new global::haxe.ds.List<object>();
		this.exits.push(new global::Shelf());

I wonder why and how I could haxe haxe declare exits as the inteface, maybe there is some workaround to this.

Thanks for any help