diff --git a/doc/src/sgml/regress.sgml b/doc/src/sgml/regress.sgml
index e0df024939..485084748c 100644
--- a/doc/src/sgml/regress.sgml
+++ b/doc/src/sgml/regress.sgml
@@ -737,6 +737,8 @@ make check PROVE_TESTS='t/001_test1.pl t/003_test3.pl'
    <para>
     The TAP tests require the Perl module <literal>IPC::Run</literal>.
     This module is available from CPAN or an operating system package.
+    They also require <productname>PostgreSQL</productname> to be
+    configured with the option <option>--enable-tap-tests</option>.
    </para>
   </sect1>