diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 665bf7a930b26b5d40448f9b7ed92eea1ac7519f..5419e7da82ba5a2729f65192efa60fd38b5e1bd6 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -204,7 +204,7 @@ static inline struct uffd_msg userfault_msg(unsigned long address,
 		 */
 		msg.arg.pagefault.flags |= UFFD_PAGEFAULT_FLAG_WP;
 	if (features & UFFD_FEATURE_THREAD_ID)
-		msg.arg.pagefault.ptid = task_pid_vnr(current);
+		msg.arg.pagefault.feat.ptid = task_pid_vnr(current);
 	return msg;
 }
 
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 2b24c28d99a734119796977a6569fcdf0577de92..d6d1f65cb3c37c7b76738f544e6b625ebff39edb 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -80,7 +80,9 @@ struct uffd_msg {
 		struct {
 			__u64	flags;
 			__u64	address;
-			__u32   ptid;
+			union {
+				__u32 ptid;
+			} feat;
 		} pagefault;
 
 		struct {