diff --git a/source/core/update.txt b/source/core/update.txt
index 0e2e5de842f..1bae1927572 100644
--- a/source/core/update.txt
+++ b/source/core/update.txt
@@ -171,8 +171,8 @@ Update an Element without Specifying Its Position
 
 The :method:`~db.collection.update()` method can perform the
 update using the :operator:`$` positional operator if the position is
-not known. The array field must appear in the ``query`` argument in
-order to determine which array element to update.
+not known. The array field must appear in the ``query`` argument as
+the last item in order to determine which array element to update.
 
 The following operation queries the ``bios`` collection for the first
 document where the ``_id`` field equals ``3`` and the ``contribs``