diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index a83c63cd98..c042300c8c 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -306,8 +306,9 @@ make prefix=/usr/local/pgsql.new install
      into the new cluster, e.g., <filename>pgcrypto.so</filename>,
      whether they are from <filename>contrib</filename>
      or some other source. Do not install the schema definitions, e.g.,
-     <command>CREATE EXTENSION pgcrypto</command>, because these will be upgraded
-     from the old cluster.
+     <command>CREATE EXTENSION pgcrypto</command>, because these will be copied
+     from the old cluster.  (Consider upgrading the extensions later
+     using <literal>ALTER EXTENSION...UPGRADE</literal>.)
      Also, any custom full text search files (dictionary, synonym,
      thesaurus, stop words) must also be copied to the new cluster.
     </para>