diff --git a/lodash.js b/lodash.js
index a03cb8c2f..920876be3 100644
--- a/lodash.js
+++ b/lodash.js
@@ -2628,7 +2628,7 @@
             result = '';
 
         while (++index < length) {
-          result = callback(result, array[index], index, words);
+          result = callback(result, array[index], index);
         }
         return result;
       };