@MultipartForm does not support lists in POJO forms

I have the following form class where the list parameter comes from a <select multiple> in the HTML UI.

public class MyForm {

	@FormParam("list")
	List<Integer> list;
}

@POST
@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
public Response urlEncoded(@BeanParam MyForm form) { ... }

When I add a method to handle multipart/form-data (because a file could also be uploaded at the same time) with @MultipartForm

@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response multipart(@MultipartForm MyForm form) { ... }

the list parameter stopped working and I got the following error:

RESTEASY007545: Unable to find a MessageBodyReader for media type: text/plain; charset=us-ascii and class type java.util.List

So, java.util.List's seem to work when they are sent in urlencoded forms (list=3&list=5&list=8) but not anymore when sent in multipart (where there are multiple parts with the same name list). It seems like resteasy wants a MBR to convert a single part into a list whereas it should convert each part separately and give the result in a list.