Peko will now be under contract through the 2016 season. He was due $4.125 million for the 2014 season, which was slated to be his last before the extension.
Peko has been able to work well in tandem with fellow defensive tackle Geno Atkins.
Peko has spent his entire eight-year career with the Bengals. He's combined for 398 tackles and totaled 12.5 sacks during his time in Cincinnati.
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Aaron Wilson covers the Ravens for The Baltimore Sun.