There is disclosed an exhaust nozzle for a gas turbine engine, the exhaust nozzle comprising a frame extending along a longitudinal axis. The exhaust nozzle comprises a convergent petal pivotably attached at a convergent pivot point to the frame and extending axially downstream and radially inward from the frame, a follower roller fixed to the convergent petal on a radially outer side of the convergent petal, and a cam defining a working surface configured to engage the follower roller to react a force from the convergent petal. The cam is movable along a travel in an axial direction to actuate radial movement of the follower roller to pivot the convergent petal. The cam defines a concave working surface such that a contact angle between the follower roller and the cam varies along the travel to thereby vary a radial component of the force reacted by the cam.