diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 11ab8c1c368..ca905b80a6d 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -7836,6 +7836,16 @@ myEventProc(PGEventId evtId, void *evtInfo, void *passThrough)
      </para>
     </listitem>
 
+    <listitem>
+     <para>
+      <indexterm>
+       <primary><envar>PGSSLCRLDIR</envar></primary>
+      </indexterm>
+      <envar>PGSSLCRLDIR</envar> behaves the same as the <xref
+      linkend="libpq-connect-sslcrldir"/> connection parameter.
+     </para>
+    </listitem>
+
     <listitem>
      <para>
       <indexterm>