A variable-nozzle assembly for a turbocharger includes a generally annular nozzle ring and an array of vanes rotatably mounted to the nozzle ring such that the vanes can be pivoted about their axes for regulating exhaust gas flow to the turbine wheel. A unison ring engages vane arms that are affixed to axles of the vanes, such that rotation of the unison ring causes the vanes to pivot between a closed position and an open position. The vanes have proximal ends that are adjacent a face of the nozzle ring. A vane sealing member is supported on the nozzle ring and has a portion disposed between the proximal ends of the vanes and the face of the nozzle ring. The unison ring includes cams that engage cam followers. Rotational movement of the unison ring causes the cam followers to be moved axially and thereby urge the vane sealing member against the proximal ends of the vanes.