diff --git a/addon/helpers/sum.js b/addon/helpers/sum.js
index cccbf98c6..6c4d73335 100644
--- a/addon/helpers/sum.js
+++ b/addon/helpers/sum.js
@@ -11,8 +11,8 @@ import { add } from './add';
  * @param {number[]} numbers A list of numbers to sum
  * @return {number} The sum of all the passed numbers
  */
-export function sum(numbers) {
-  return add(numbers);
+export function sum() {
+  return add(...arguments);
 }
 
 export default helper(sum);