diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml
index d5df65bc693..e7f409ddd64 100644
--- a/doc/src/sgml/wal.sgml
+++ b/doc/src/sgml/wal.sgml
@@ -643,6 +643,9 @@
    until the situation is resolved. A slow or failed standby server that
    uses a replication slot will have the same effect (see
    <xref linkend="streaming-replication-slots"/>).
+   Similarly, if <link linkend="runtime-config-wal-summarization">
+   WAL summarization</link> is enabled, old segments are kept
+   until they are summarized.
   </para>
 
   <para>