An adjustment mechanism for an air inlet flow section of a compressor wheel of a turbocharger. The adjustment mechanism defines a variable inlet diameter for an axial air flow to the compressor wheel. The adjustment mechanism has a unison ring and a plurality of vanes. An actuator is used for providing a first pivoting motion to the unison ring about a central axis and thereby providing a second pivoting motion to the plurality of vanes. At least one elastic biaser is arranged, such that it provides, upon the pivoting motion to the unison ring, a restoring force to the unison ring and/or the plurality of vanes. The pivoting motion of the vanes adjusts the inlet diameter of the axial air flow to the compressor wheel.