Abstract: An auxiliary brake light for motor vehicles which consists of a socket mounted securely on the hat storage shelf and of a light housing pivotally mounted on the socket toward the rear window; the auxiliary brake light includes means for sealing the light exit surface with respect to the rear window for preventing stray light; the light housing is displaceably and pivotally connected with the socket by way of bolts engaging in guide channels and at least one springy tongue projects from the socket which is adapted to be connected with the light housing in a detent-like manner.