A lighting unit includes a housing, a lamp fixture configured to be coupled to the housing, an element extending from the lamp fixture and configured to be received in the housing, and a sealing member defining an aperture for receiving the element therethrough. A periphery of the aperture forms a fluid-tight seal around the element. In another aspect, a lighting unit includes a housing and an enclosure coupled to the housing and configured to define an interior space, wherein the interior space is sealed from an interior of the housing. In another aspect, a method for sealing a lighting unit includes providing a housing, an enclosure coupled to the housing, and an opening in the housing in communication with the enclosure, placing a seal between the housing and the enclosure, and applying a sealing member to the opening to seal the opening.