An exhaust-gas turbocharger for an internal combustion engine includes an intake duct for air, an exhaust-gas duct, a turbine arranged in the exhaust-gas duct, and a compressor impeller arranged in the intake duct, which turbine and compressor impeller are both arranged on a common shaft, wherein the exhaust-gas duct has a spiral housing which coaxially surrounds the turbine, and wherein, between the spiral housing and the turbine, a ring-shaped gap is provided through which the exhaust-gas flow flows circumferentially to the turbine, and wherein, in the ring-shaped gap, guide vanes are arranged which are rotatable about an adjustment axis by an adjustment mechanism for controlling the flow resistance. To compensate thermal expansions and shrinkages of the guide vanes under different operating conditions, the adjustment mechanism additionally has a displacement mechanism for displacing the guide vanes in the ring-shaped gap. The displacement mechanism is directly coupled to the adjustment mechanism.