Abstract: A luminaire can comprise a top housing fastened to a bottom housing, the top housing comprising at least one rib, the luminaire further comprising a lightguide disposed between the top housing and the bottom housing, the rib securing the lightguide against a gasket, wherein the gasket is located between the lightguide and the bottom housing, and the luminaire further comprising a light source disposed between the top housing and the bottom housing and further disposed adjacent an edge of the lightguide. The bottom housing can define an opening through which light emitted by the lightguide exits the luminaire.