A variable geometry turbine comprises: a turbine wheel (5) in a housing (1) for rotation about a turbine axis, an annular inlet passage (9) defined between respective radial inlet surfaces of first and second wall members (11, 12), at least one of said first and second wall members being moveable along the turbine axis to vary the size of the inlet passage; an array of vanes (14) extending across the inlet passage, said vanes being connected to said first wall member; a complementary array of vane slots (28) defined by the second wall member, said vane slots configured to receive said vanes to accommodate relative movement between the first and second wall members; the second wall member comprising at least two axially adjacent co-axial plates (29, 30), a first plate (29) defining a first array of openings which overlie a second array of openings defined by a second plate (30) so as to define said array of vane slots, said first plate being fixed to said second plate.