diff --git a/includes/jquery.drilldown.js b/includes/jquery.drilldown.js
index 5e085fb..ae18fbc 100644
--- a/includes/jquery.drilldown.js
+++ b/includes/jquery.drilldown.js
@@ -83,10 +83,11 @@
if (breadcrumb[key]) {
// We don't use the $().clone() method here because of an
// IE & jQuery 1.2 bug.
- var clone = $('')
- .attr('href', $(breadcrumb[key]).attr('href'))
- .attr('class', $(breadcrumb[key]).attr('class'))
- .html($(breadcrumb[key]).html())
+ var clone = $('');
+ // attr() may return undefined since jquery 1.6
+ clone.attr('href', $(breadcrumb[key]).attr('href'));
+ clone.attr('class', $(breadcrumb[key]).attr('class'));
+ clone.html($(breadcrumb[key]).html())
.addClass('depth-'+key)
.appendTo(trail);