diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index fb8d0bca86ae4e9eaedf9feaf13a04ff3c58cda3..5e6ecacb74496dac71c0f3973d0054717d7c9ed7 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -23,6 +23,9 @@
 # server for the changes to take effect, or use "pg_ctl reload". Some
 # settings, which are marked below, require a server shutdown and restart
 # to take effect.
+#
+# Memory units:  kB = kilobytes MB = megabytes GB = gigabytes
+# Time units:    ms = milliseconds s = seconds min = minutes h = hours d = days
 
 
 #---------------------------------------------------------------------------