WP REST API post__in filter does not work

I’m writing a angular app, that requests contents from a WordPress site vie WP REST API Plugin.
I want to filter the posts by id, but i get all posts as result.

$http.get("https://meinedomain.de/wp-json/posts/", {
            params: {
                "filter[post__in][]": 91,
                "filter[post__in][]": 92
            }
        }).success(function(data) {
            console.log(data)
        }).error(function(data) {
            console.log("ERROR: " + data);
        });