@JsExport issues on abstract function

Is there allowed to annotate @JsExport on abstract classes ?

abstract class SampleClass(id: Int, name: String) {
    var id: Int? = id
    var name: String? = name

    abstract fun description(text: String): String

error after build is … @JsExport is only allowed on files and top-level declarations
If I remove @JsExport from abstract function, it will not be exported in JS.
How to solve this ?