diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index d768ea065c5..02b89b01e38 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -168,6 +168,11 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
    of the current command being executed by any server process.
   </para>
 
+  <para>
+   The parameter <xref linkend="guc-track-cost-delay-timing"/> enables
+   monitoring of cost-based vacuum delay.
+  </para>
+
   <para>
    The parameter <xref linkend="guc-track-counts"/> controls whether
    cumulative statistics are collected about table and index accesses.