diff --git a/source/core/sharded-cluster-config-servers.txt b/source/core/sharded-cluster-config-servers.txt
index fd9d1494d39..03b0b8ac4e8 100644
--- a/source/core/sharded-cluster-config-servers.txt
+++ b/source/core/sharded-cluster-config-servers.txt
@@ -40,9 +40,15 @@ Replica Set Config Servers
 .. include:: /includes/fact-config-server-replica-set-restrictions.rst
 
 Earlier versions of MongoDB required *exactly three* mirrored
-:program:`mongod` instances to act as the config servers. MongoDB 3.2
-deprecates the use of three mirrored :program:`mongod` instances for
-config servers.
+:program:`mongod` instances to act as the config servers. If you are using
+*mirrored* config servers, each server's system clock must be within 30
+seconds of each other server for the distributed lock manager to work
+properly. With *mirrored* config servers, minimize clock skew by running the
+network time protocol (NTP) ``ntpd`` on your servers. MongoDB 3.2 deprecates
+the use of three mirrored :program:`mongod` instances for config servers.
+
+With replica set config servers, clock skew does not affect distributed lock
+management.
 
 Each sharded cluster must have its own config servers. Do not use the
 same config servers for different sharded clusters.