diff --git a/sys/sys/file.h b/sys/sys/file.h
--- a/sys/sys/file.h
+++ b/sys/sys/file.h
@@ -132,6 +132,7 @@
 typedef int fo_fspacectl_t(struct file *fp, int cmd,
 		    off_t *offset, off_t *length, int flags,
 		    struct ucred *active_cred, struct thread *td);
+typedef int fo_spare_t(struct file *fp);
 typedef	int fo_flags_t;
 
 struct fileops {
@@ -154,6 +155,7 @@
 	fo_get_seals_t	*fo_get_seals;
 	fo_fallocate_t	*fo_fallocate;
 	fo_fspacectl_t	*fo_fspacectl;
+	fo_spare_t	*fo_spares[8];	/* Spare slots */
 	fo_flags_t	fo_flags;	/* DFLAG_* below */
 };
 
diff --git a/sys/sys/param.h b/sys/sys/param.h
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -76,7 +76,7 @@
  * cannot include sys/param.h and should only be updated here.
  */
 #undef __FreeBSD_version
-#define __FreeBSD_version 1400073
+#define __FreeBSD_version 1400074
 
 /*
  * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,