A lighting and/or signalling device, in particular for a motor vehicle, comprising at least one light source emitting light rays and at least one optical guide in which the light beam spreads, the at least one optical guide comprising at at least one of its ends an input face coupling the at least one optical guide and the at least one light source, a first surface forming an output face for the light beam, and a second surface, in particular remote from the output face, forming a face for reflection of the light rays, such that the at least one optical guide has at least one bend, the at least one optical guide in the region of the at least one bend having at least one corner protruding toward the outside of the at least one bend and bevelled by having two facets in order to send back the incident rays into the at least one optical guide.