The unexpected announcement this morning that AMC and showrunner Glen Mazzara "have mutually decided to part ways" is accompanied by confirmation that The Walking Dead will return for a fourth season.

"AMC and Glen Mazzara have jointly announced that for future seasons of The Walking Dead, the two parties have mutually decided to part ways," the network wrote in the statement. "Glen guided the series creatively for seasons 2 and 3. This decision is amicable and Glen will remain on for post-production on season 3B as showrunner and executive producer."

Given the ratings of the hit drama, that news comes as less of a surprise than the departure of its second showrunner in a little more than a year. (Frank Darabont, who developed the adaptation of the acclaimed comic book for television, was fired by the network in July 2011.) The Dec. 2 midseason finale drew a record 10. 5 million viewers in its initial airing, and 15.2 million for the night.

That episode also set the stage for a major confrontation between Rick and the other survivors at the Prison and The Governor's forces in Woodbury. The Walking Dead returns from its midseason hiatus Sunday, Feb. 10.