diff --git a/js-bench/for_vs_map.js b/js-bench/for_vs_map.js
index ed41e0b..7635d8f 100644
--- a/js-bench/for_vs_map.js
+++ b/js-bench/for_vs_map.js
@@ -8,7 +8,7 @@ const for_timings = []
 for (let i = 0; i < 10; i++) {
     const startTime = performance.now()
     for (let i = 0; i < for_test_list.length; i++) { 
-        for_test_list[i] * 2
+        for_test_list[i] = for_test_list[i] * 2
     } 
     const timeElapsed = performance.now() - startTime
     for_timings.push(timeElapsed)