Longitudinal luminaire extending along a longitudinal axis, comprising: a longitudinal track profile delimiting an interior space, wherein the track profile comprises a longitudinal opening to access the interior space, a longitudinal light source being provided in the interior space and extending in parallel to the longitudinal axis, the light source comprising a longitudinal PCB being equipped with a plurality of LEDs arranged in a row, a plurality of optical elements being integrally formed as an optical group and arranged in a row corresponding to the LEDs so that each of the optical elements can be functionally positioned to at least one of the LEDs when the optical group is attached to the track profile so that the optical elements can optically influence light emitted from the associated LEDs, and an attachment clip comprising: • a first attachment section to be attached to a corresponding second attachment section of the track profile for holding the attachment clip at the track profile at least in a direction orthogonal to the longitudinal axis, • a first fixing section for relatively fixing the light source via a corresponding second fixing section of the light source with respect to the attachment clip, and • a first alignment section for alignment of the attachment clip relative to the optical group via a corresponding second alignment section of the optical group so that each of the optical elements are functionally positioned to the associated LEDs wherein the optical group comprises a first holding section and the track profile comprises a second holding structure for mechanically cooperating with the first holding section to attach the optical group to the track profile. a longitudinal track profile delimiting an interior space, wherein the track profile comprises a longitudinal opening to access the interior space, a longitudinal light source being provided in the interior space and extending in parallel to the longitudinal axis, the light source comprising a longitudinal PCB being equipped with a plurality of LEDs arranged in a row, a plurality of optical elements being integrally formed as an optical group and arranged in a row corresponding to the LEDs so that each of the optical elements can be functionally positioned to at least one of the LEDs when the optical group is attached to the track profile so that the optical elements can optically influence light emitted from the associated LEDs, and an attachment clip comprising: • a first attachment section to be attached to a corresponding second attachment section of the track profile for holding the attachment clip at the track profile at least in a direction orthogonal to the longitudinal axis, • a first fixing section for relatively fixing the light source via a corresponding second fixing section of the light source with respect to the attachment clip, and • a first alignment section for alignment of the attachment clip relative to the optical group via a corresponding second alignment section of the optical group so that each of the optical elements are functionally positioned to the associated LEDs • a first attachment section to be attached to a corresponding second attachment section of the track profile for holding the attachment clip at the track profile at least in a direction orthogonal to the longitudinal axis, • a first fixing section for relatively fixing the light source via a corresponding second fixing section of the light source with respect to the attachment clip, and • a first alignment section for alignment of the attachment clip relative to the optical group via a corresponding second alignment section of the optical group so that each of the optical elements are functionally positioned to the associated LEDs wherein the optical group comprises a first holding section and the track profile comprises a second holding structure for mechanically cooperating with the first holding section to attach the optical group to the track profile.