diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index 5826a1730..21336dc29 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -705,7 +705,6 @@ class ModelSerializer(Serializer):
                     setattr(related, fk_field, obj)
                     self.save_object(related)
                 else:
-                    setattr(self.object, accessor_name, related)
                     setattr(obj, accessor_name, related)
             del(obj._related_data)