diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index c95bbb9e5a7..af3e9a71656 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -3909,8 +3909,9 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
VACUUM is currently vacuuming the indexes. If a table has
any indexes, this will happen at least once per vacuum, after the heap
has been completely scanned. It may happen multiple times per vacuum
- if is insufficient to
- store the number of dead tuples found.
+ if (or, in the case of autovacuum,
+ if set) is insufficient to store
+ the number of dead tuples found.