diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index c8e8d030457..487bb103637 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -18335,6 +18335,10 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
the role (that is, the right to do SET ROLE), while
USAGE denotes whether the privileges of the role
are immediately available without doing SET ROLE.
+ WITH ADMIN OPTION or WITH GRANT
+ OPTION can be added to either of these privilege types to
+ test whether the ADMIN privilege is held (all
+ four spellings test the same thing).