The invention relates to a device for fastening at least a first component having a through-opening on at least a second component also having a through-opening, comprising a fastening bushing with a sleeve section which is designed to be inserted through the through-openings of the components and with a sleeve head, wherein the sleeve section comprises at least one locking section and at least two recesses extending in an axial direction in its wall, and wherein the sleeve head comprises a through-opening aligned with the sleeve section, a fastening pin with a pin section and with a pin head, wherein the pin head comprises at least one locking section and wherein stop means are provided between the fastening pin and the fastening bushing, wherein the pin section is inserted through the sleeve section and the through-opening of the sleeve head until reaching the stop provided by the stop means, wherein the pin head engages with the free end of the sleeve section being opposite to the sleeve head, and a water-tight sheath, which surrounds the sleeve section and the pin head engaging the sleeve section, wherein the fastening pin is designed to be pulled further through the through-opening of the sleeve head until the locking section of the pin head locks with the locking section of the sleeve section, and wherein the walls of the sleeve section and the sheath spread, whereby the sleeve section and the sheath reduce in length.