diff --git a/fs/stat.c b/fs/stat.c
index ab27f2868588..0c7e6cdc435c 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -562,6 +562,8 @@ SYSCALL_DEFINE5(statx,
 	struct kstat stat;
 	int error;
 
+	if (mask & STATX__RESERVED)
+		return -EINVAL;
 	if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
 		return -EINVAL;
 
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 51a6b86e3700..0869b9eaa8ce 100644
--- a/include/uapi/linux/stat.h
+++ b/include/uapi/linux/stat.h
@@ -152,6 +152,7 @@ struct statx {
 #define STATX_BASIC_STATS	0x000007ffU	/* The stuff in the normal stat struct */
 #define STATX_BTIME		0x00000800U	/* Want/got stx_btime */
 #define STATX_ALL		0x00000fffU	/* All currently supported flags */
+#define STATX__RESERVED		0x80000000U	/* Reserved for future struct statx expansion */
 
 /*
  * Attributes to be found in stx_attributes