diff --git a/source/reference/command/shardCollection.txt b/source/reference/command/shardCollection.txt
index 9759e6aff67..47c41a05dd5 100644
--- a/source/reference/command/shardCollection.txt
+++ b/source/reference/command/shardCollection.txt
@@ -19,6 +19,12 @@ Definition
 
       { shardCollection: "<database>.<collection>", key: <shardkey> }
 
+   .. warning::
+
+      Do not run multiple concurrent :dbcommand:`shardCollection`
+      commands on the same collection. Doing so may cause
+      inconsistencies between config servers.
+
    :dbcommand:`shardCollection` has the following fields:
 
    .. include:: /reference/command/shardCollection-field.rst