diff --git a/js/lib/d3.combobox.js b/js/lib/d3.combobox.js
index 2f8a69bc3..75fa9b03d 100644
--- a/js/lib/d3.combobox.js
+++ b/js/lib/d3.combobox.js
@@ -290,5 +290,3 @@ d3.combobox = function() {
 
     return d3.rebind(combobox, event, 'on');
 };
-
-d3.combobox.id = 0;