diff --git a/docs/production/system-configuration.md b/docs/production/system-configuration.md
index 28c4f8fb16..2157436b77 100644
--- a/docs/production/system-configuration.md
+++ b/docs/production/system-configuration.md
@@ -236,7 +236,10 @@ setting](https://www.postgresql.org/docs/current/runtime-config-connection.html#
 #### `random_page_cost`
 
 Override PostgreSQL's [`random_page_cost`
-setting](https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-RANDOM-PAGE-COST)
+setting](https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-RANDOM-PAGE-COST).
+Zulip defaults this value to 1.1, which is an appropriate value for
+SSDs; if your server uses spinning disks, you should set this back to
+the upstream default of 4.0.
 
 #### `replication_primary`
 
diff --git a/puppet/zulip/manifests/profile/postgresql.pp b/puppet/zulip/manifests/profile/postgresql.pp
index b288c1f680..1303e8ded8 100644
--- a/puppet/zulip/manifests/profile/postgresql.pp
+++ b/puppet/zulip/manifests/profile/postgresql.pp
@@ -23,7 +23,7 @@ class zulip::profile::postgresql(Boolean $start = true) {
   $wal_buffers = zulipconf('postgresql', 'wal_buffers', undef)
   $min_wal_size = zulipconf('postgresql', 'min_wal_size', undef)
   $max_wal_size = zulipconf('postgresql', 'max_wal_size', undef)
-  $random_page_cost = zulipconf('postgresql', 'random_page_cost', undef)
+  $random_page_cost = zulipconf('postgresql', 'random_page_cost', '1.1')
   $effective_io_concurrency = zulipconf('postgresql', 'effective_io_concurrency', undef)
 
   $listen_addresses = zulipconf('postgresql', 'listen_addresses', undef)