diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 9a52f347ffd..5641c1a2ae6 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2848,6 +2848,7 @@ local0.*    /var/log/postgresql
         cluster data directory.
         This parameter can only be set in the <filename>postgresql.conf</>
         file or on the server command line.
+        The default is <literal>pg_log</literal>.
        </para>
       </listitem>
      </varlistentry>
@@ -2869,6 +2870,7 @@ local0.*    /var/log/postgresql
         by <xref linkend="guc-log-timezone">.)
         Note that the system's <systemitem>strftime</systemitem> is not used
         directly, so platform-specific (nonstandard) extensions do not work.
+        The default is <literal>postgresql-%Y-%m-%d_%H%M%S.log</literal>.
        </para>
        <para>
         If you specify a file name without escapes, you should plan to
@@ -2885,8 +2887,6 @@ local0.*    /var/log/postgresql
         log file name to create the file name for CSV-format output.
         (If <varname>log_filename</> ends in <literal>.log</>, the suffix is
         replaced instead.)
-        In the case of the example above, the CSV
-        file name will be <literal>server_log.1093827753.csv</literal>.
        </para>
        <para>
         This parameter can only be set in the <filename>postgresql.conf</>