diff --git a/libc/include/sys/mount.h b/libc/include/sys/mount.h
index ba88447..207527e 100644
--- a/libc/include/sys/mount.h
+++ b/libc/include/sys/mount.h
@@ -51,7 +51,10 @@
 #define MS_REC          16384
 #define MS_VERBOSE      32768
 #define MS_POSIXACL     (1<<16) /* VFS does not apply the umask */
-#define MS_ONE_SECOND   (1<<17) /* fs has 1 sec a/m/ctime resolution */
+#define MS_UNBINDABLE   (1<<17) /* change to unbindable */
+#define MS_PRIVATE      (1<<18) /* change to private */
+#define MS_SLAVE        (1<<19) /* change to slave */
+#define MS_SHARED       (1<<20) /* change to shared */
 #define MS_ACTIVE       (1<<30)
 #define MS_NOUSER       (1<<31)