diff --git a/libc/kernel/uapi/linux/stat.h b/libc/kernel/uapi/linux/stat.h
index 2fb7437..9974f3e 100644
--- a/libc/kernel/uapi/linux/stat.h
+++ b/libc/kernel/uapi/linux/stat.h
@@ -85,6 +85,7 @@
 #define STATX_BTIME 0x00000800U
 #define STATX_MNT_ID 0x00001000U
 #define STATX_DIOALIGN 0x00002000U
+#define STATX_MNT_ID_UNIQUE 0x00004000U
 #define STATX__RESERVED 0x80000000U
 #define STATX_ALL 0x00000fffU
 #define STATX_ATTR_COMPRESSED 0x00000004