diff --git a/doc/src/sgml/notation.sgml b/doc/src/sgml/notation.sgml
index 277a3f721e8..eec348aca63 100644
--- a/doc/src/sgml/notation.sgml
+++ b/doc/src/sgml/notation.sgml
@@ -76,7 +76,7 @@ path to the Postgres superuser's home directory.
In a command synopsis, brackets
-[
and ]
) indicate an optional phrase or keyword.
+([
and ]
) indicate an optional phrase or keyword.
Anything in braces
({
and }
) and containing vertical bars (|
)
indicates that you must choose one.