diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index c47b9139eb..764cf737c7 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -143,6 +143,15 @@ PostgreSQL documentation
connections.
+
+
+ Running initdb without arguments on platforms lacking
+ peer or Unix-domain socket connections will exit
+ with an error. On such environments, you need to either provide a
+ password or choose a different authentication method.
+
+
+
Do not use trust unless you trust all local users on your
system.