diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index f323bba018..6d03115d37 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2663,7 +2663,7 @@ include_dir 'conf.d'
          utility commands that support the use of parallel workers are
          <command>CREATE INDEX</command> only when building a B-tree index,
          and <command>VACUUM</command> without <literal>FULL</literal>
-         option.  Parallel workers are taken from the pool of processes
+         option. This parameter does not apply to autovacuum, which does not use parallelism. Parallel workers are taken from the pool of processes
          established by <xref linkend="guc-max-worker-processes"/>, limited
          by <xref linkend="guc-max-parallel-workers"/>.  Note that the requested
          number of workers may not actually be available at run time.