According to an embodiment of the present invention, there is provided a variable geometry turbine comprising: a turbine wheel mounted on a turbine shaft within a housing assembly for rotation about a turbine axis, the housing assembly defining a gas flow inlet passage upstream of the turbine wheel; an annular wall member defining a wall of the inlet passage and which is displaceable in a direction substantially parallel to the turbine axis to control gas flow through the inlet passage; at least one moveable rod operably connected via a first end of the rod to the annular wall member, the rod being moveable to control displacement of the annular wall member, the rod extending in a direction substantially parallel to the turbine axis; wherein the rod is provided with a region of reduced radius which extends only partly around the rod, the region of reduced radius being remote from a second end of the rod to which a component of an actuator assembly for moving the rod is connectable.