We present a new algorithm and implementation of a lock primitive that is based on Linux' native lock interface, the futex system call. It allows us to assemble compiler support for atomic data structures that can not be handled through specific hardware instructions. Such a tool is needed for C11's atomics interface because here an _Atomic qualification can be attached to almost any data type. Our lock data structure for that purpose meets very specific criteria concerning its field of operation and its performance. By that we are able to outperform gcc's libatomic library by around 60%.