diff --git a/src/selector.js b/src/selector.js
index ab014b5..eff1659 100644
--- a/src/selector.js
+++ b/src/selector.js
@@ -1,3 +1,7 @@
+/* Portions of the Selector class are derived from Jack Slocum’s DomQuery,
+ * part of YUI-Ext version 0.40, distributed under the terms of an MIT-style
+ * license.  Please see http://www.yui-ext.com/ for more information. */
+
 var Selector = Class.create();
 
 Selector.prototype = {