The Melissa McBride mystery over whether or not the Walking Dead actress would be upgraded to a series regular has been resolved by the McBride herself on Twitter.

The mystery started when The Walking Dead upgraded three actors to series regulars, and Melissa McBride, who plays Carol, wasn't one of them. Fans of the actress demanded that AMC, the network that airs the hit zombie apocalypse show, make her a regular as well.

However, Melissa McBride confirmed on Twitter that she always has been a series regular, hence her name not being listed on the new regulars list.

McBride tweeted, "awesome outpouring thanks! But I currently am a series regular. It's legalese, and what it means for my castmates now is CONGRATULATIONS!!"

The 'legalese' she is referring to is the fact that her name isn't included in the main title sequence with the names of co-stars Andrew Lincoln and Norman Reedus. McBride is instead listed in the secondary credits ('also starring') following the first commercial break, a section usually reserved for guest stars.

Sources told TVLine that the Walking Dead contracts give AMC and producers the right to include regulars either in the main or secondary sections.

Interestingly, Danai Gurira, who plays Michonne in Season 3, was given the honor of appearing in the main title, while McBride, who has been part of all 3 seasons, has yet to receive the honor.

Even Robert Kirkman, the series creator, can't explain the inconsistency. "There are a lot of executive producers on the show and that's not my forte. I don't even know what the series regular term actually really means when it gets down to it, I'm sorry to admit," he told TVLine. 

The Walking Dead is scheduled to air its fourth season in October on AMC. Scott M. Gimple will take control of the series in Season 4.