diff --git a/sys/sys/socket.h b/sys/sys/socket.h
index f76a4b5f3825..a38b21706073 100644
--- a/sys/sys/socket.h
+++ b/sys/sys/socket.h
@@ -542,11 +542,9 @@ int	sendfile(int, int, off_t, size_t, struct sf_hdtr *, off_t *, int);
 #endif
 int	setsockopt(int, int, int, const void *, socklen_t);
 int	shutdown(int, int);
+int	sockatmark(int);
 int	socket(int, int, int);
 int	socketpair(int, int, int, int *);
-/*
- * XXX missing sockatmark().
- */
 __END_DECLS
 
 #endif /* !_KERNEL */