A plurality of guide vanes (34) in a variable turbine geometry turbocharger (10) regulates a flow of exhaust gas. The guide vanes (34) are selectively adjustable between an open position to allow the flow of exhaust gas to drive a turbine wheel (24) and a closed position to block the flow of exhaust gas. A first flow feature (58) is disposed on first (44) and second (46) edges of the guide vanes (34) to disturb the flow of exhaust gas to prevent leakage of exhaust gas around the first (44) and second (46) edges. A second flow feature (64) is disposed on front (60) and rear (62) surfaces of the guide vanes (34) to channel the flow of exhaust gas between adjacent guide vanes (34) when the guide vanes (34) are in the open position to prevent swirling and/or cross flow of the exhaust gas.