diff --git a/lib/buster-istanbul.js b/lib/buster-istanbul.js
index 7f35525..49d7a87 100644
--- a/lib/buster-istanbul.js
+++ b/lib/buster-istanbul.js
@@ -60,7 +60,7 @@ var setup = {
     });
   },
 
-  browser: function(group) {
+  browser: function(group, instrument) {
     var options = group.config.options;
 
     global['__coverage__'] = global['__coverage__'] || {};