Our whole universe… is getting more populated, now that The Big Bang Theory has added Kevin Sussman as a series regular for Season 6, our sister site Deadline reports.

Sussman, who has recurred since Season 2 as Stuart, the owner of the Marvel-lite comic book shop, becomes the CBS hitcom’s eighth series regular, joining Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayar, Melissa Rauch and Mayim Bialik.

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That said, the frequency of his appearances is likely to remain intermittent, meaning he won’t appear in every episode like the others. The actor’s previous TV credits include a recent episode of Weeds, My Name Is Earl and Ugly Betty.

Big Bang opens its new season on Thursday, Sept. 27 at 8/7c, where it will now lead into Two and a Half Men.