Kouandjio signed a contract with the Lions on Thursday, Field Yates of ESPN.com reports.
Kouandjio, a former second-round pick of the Bills, largely struggled during his first three seasons and was eventually let go by the Bills at the end of May. The Lions, however, just lost fellow tackle Taylor Decker for at least the next four months because of a shoulder injury, so Kouandjio will be brought in for additional help on the line in Detroit. The Lions also recently traded for tackle Greg Robinson, so Kouandjio isn't guaranteed significant snaps or even a spot on the final roster.