diff --git a/libc/kernel/uapi/linux/mount.h b/libc/kernel/uapi/linux/mount.h
index 13d0581..2099b48 100644
--- a/libc/kernel/uapi/linux/mount.h
+++ b/libc/kernel/uapi/linux/mount.h
@@ -62,7 +62,8 @@
 #define MOVE_MOUNT_T_SYMLINKS 0x00000010
 #define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020
 #define MOVE_MOUNT_T_EMPTY_PATH 0x00000040
-#define MOVE_MOUNT__MASK 0x00000077
+#define MOVE_MOUNT_SET_GROUP 0x00000100
+#define MOVE_MOUNT__MASK 0x00000177
 #define FSOPEN_CLOEXEC 0x00000001
 #define FSPICK_CLOEXEC 0x00000001
 #define FSPICK_SYMLINK_NOFOLLOW 0x00000002