diff --git a/AUTHORS b/AUTHORS
index 02c312e4ca..75b947b1b8 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -382,6 +382,7 @@ answer newbie questions, and generally made Django that much better:
     Jökull Sólberg Auðunsson <jokullsolberg@gmail.com>
     Jon Dufresne <jon.dufresne@gmail.com>
     Jonas Haag <jonas@lophus.org>
+    Jonatas C. D. <jonatas.cd@gmail.com>
     Jonathan Buchanan <jonathan.buchanan@gmail.com>
     Jonathan Daugherty (cygnus) <http://www.cprogrammer.org/>
     Jonathan Feignberg <jdf@pobox.com>
diff --git a/docs/ref/models/fields.txt b/docs/ref/models/fields.txt
index 6c9c5057c2..c50f09b401 100644
--- a/docs/ref/models/fields.txt
+++ b/docs/ref/models/fields.txt
@@ -1424,7 +1424,8 @@ The possible values for :attr:`~ForeignKey.on_delete` are found in
 .. attribute:: ForeignKey.to_field
 
     The field on the related object that the relation is to. By default, Django
-    uses the primary key of the related object.
+    uses the primary key of the related object. If you reference a different
+    field, that field must have ``unique=True``.
 
 .. attribute:: ForeignKey.db_constraint