diff --git a/activerecord/lib/active_record/serializers/xml_serializer.rb b/activerecord/lib/active_record/serializers/xml_serializer.rb
index f8e6cf958c25ce22dd805a473619b73780384c65..67f6c7833c6cb9edec4b0f5832a70f6c2b8e9077 100644
--- a/activerecord/lib/active_record/serializers/xml_serializer.rb
+++ b/activerecord/lib/active_record/serializers/xml_serializer.rb
@@ -219,8 +219,8 @@ def add_associations(association, records, opts)
             end
           end
         end
-      elsif record = @serializable.send(association)
-        record.to_xml(merged_options)
+      else
+        records.to_xml(merged_options)
       end
     end