[FOSDEM] How to include a co-speaker for a talk

Hi, I have submitted a proposal for a talk i.e. "The CentOS Storage SIG and GlusterFS" in "Distribution devroom" track. This talk/lecture will be done by me and Kaleb (CC'ed). But I could not find a way in Pentabarf to add him as a co-speaker. Kindly let me know how I can do that. Thanks, Lala