diff --git a/libc/kernel/uapi/linux/socket.h b/libc/kernel/uapi/linux/socket.h
index 7ce5304..be16548 100644
--- a/libc/kernel/uapi/linux/socket.h
+++ b/libc/kernel/uapi/linux/socket.h
@@ -29,4 +29,7 @@
     void * __align;
   };
 };
+#define SOCK_SNDBUF_LOCK 1
+#define SOCK_RCVBUF_LOCK 2
+#define SOCK_BUF_LOCK_MASK (SOCK_SNDBUF_LOCK | SOCK_RCVBUF_LOCK)
 #endif