Fox's "X-Files" reboot will officially welcome back another veteran alongside David Duchovny and Gillian Anderson. Mitch Pileggi has signed on to join the six-episode revival series.

Pileggi tweeted the news on Monday.

The actor starred as Walter Skinner, Mulder and Scully's boss and friend, though occasionally an enemy, throughout "The X-Files'" nine-season run. He also appeared in both movies and the short-lived spin-off "The Lone Gunmen."

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Pileggi had been rumored to return for weeks, and Duchovny teased his possible return during a recent interview with David Letterman.

Pileggi has most recently appeared on "Dallas," "Sons of Anarchy" and "Grey's Anatomy."