The invention relates to an assembly for a turbomachine, comprising: —a nacelle comprising an inlet lip which defines an air inlet, and—a device for modifying the geometry of the air inlet, comprising: —a first spout, and—a second spout, the first spout and the second spout being translatably movable in relation the nacelle between: —a first configuration, in which the first spout forms the inlet lip and the second spout extends inside the nacelle, and—a second configuration, in which the first spout extends away from the inlet lip, and the second spout forms the inlet lip so as to define an air flow channel between a downstream surface of the first spout and an upstream surface of the second spout.