diff --git a/include/sys/zfs_vfsops.h b/include/sys/zfs_vfsops.h
index c3b15226d9b3..28407c6f76fe 100644
--- a/include/sys/zfs_vfsops.h
+++ b/include/sys/zfs_vfsops.h
@@ -112,7 +112,7 @@ typedef struct zfs_sb {
 	uint64_t	z_groupquota_obj;
 	uint64_t	z_replay_eof;	/* New end of file - replay only */
 	sa_attr_type_t	*z_attr_table;	/* SA attr mapping->id */
-#define	ZFS_OBJ_MTX_SZ	768
+#define	ZFS_OBJ_MTX_SZ	256
 	kmutex_t	*z_hold_mtx;	/* znode hold locks */
 } zfs_sb_t;