A damper ring is mounted in frictional engagement with a radially inwardly facing surface of a circumferential groove defined in a rotary part of a gas turbine engine. Energy dissipation is provided via sliding friction of the ring in the groove. The damper ring has a circumferentially segmented ring body having a non-uniform circumferential stiffness around its circumference including a locally reduced stiffness in a circumferential direction between each pair of circumferentially adjacent ring segments.