diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index c2cdde77f31..13998a458c0 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -882,7 +882,8 @@ psql: could not connect to server: No such file or directory
When using POSIX semaphores, the number of semaphores needed is the
same as for System V, that is one semaphore per allowed connection
(), allowed autovacuum worker process
- () and allowed background
+ (), allowed WAL sender process
+ (), and allowed background
process ().
On the platforms where this option is preferred, there is no specific
kernel limit on the number of POSIX semaphores.