REST API Logout not working with CURL?

Hi, I'm trying to work with SDL WorldServer REST API using CURL, I am able to log in, get info about project groups, download scope, but I am not able to log out. then.
Calling the following command:
curl -H "Content-Type:application/json"  -X POST "%SDL_WS_SERVER%/ws-api/v1/logout?token=%SESSION_ID%"

Geting the following error:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""">www.w3.org/.../strict.dtd">
<HTML><HEAD><TITLE>Length Required</TITLE>
<META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>
<BODY><h2>Length Required</h2>
<hr><p>HTTP Error 411. The request must be chunked or have a content length.</p>
</BODY></HTML>

Could you please give me some hint?

Thanks a lot in advance!

Best regards,

Jan