diff --git a/exercises/implement_map_with_reduce/solution/solution.js b/exercises/implement_map_with_reduce/solution/solution.js
index 170e47f..7855ff7 100644
--- a/exercises/implement_map_with_reduce/solution/solution.js
+++ b/exercises/implement_map_with_reduce/solution/solution.js
@@ -1,6 +1,6 @@
 module.exports = function arrayMap(arr, fn, thisArg) {
-  return arr.reduce(function(acc, item, index, arr) {
-    acc.push(fn.call(thisArg, item, index, arr))
+  return arr.reduce(function(acc, item) {
+    acc.push(fn.call(thisArg, item))
     return acc
   }, [])
 }