diff --git a/benchmark/benchmark.js b/benchmark/benchmark.js
index 5bb1359..682ecf8 100644
--- a/benchmark/benchmark.js
+++ b/benchmark/benchmark.js
@@ -1,19 +1,19 @@
 $(function() {
-    var running = false;
+    let running = false;
     $("#runall").click(function() {
         if (running) {
             return;
         }
         running = true;
 
-        var graph = new Graph(grid),
+        let graph = new Graph(grid),
             start = graph.grid[0][0],
             end = graph.grid[140][140],
             results = [],
             times = 0;
 
-        for (var i = 0; i < 1000; i++) {
-            var startTime = performance ? performance.now() : new Date().getTime(),
+        for (let i = 0; i < 1000; i++) {
+            let startTime = performance ? performance.now() : new Date().getTime(),
                 result = astar.search(graph, start, end),
                 endTime = performance ? performance.now() : new Date().getTime();
             times = times + (endTime - startTime);
@@ -31,4 +31,4 @@ $(function() {
         running = false;
         return false;
     });
-});
\ No newline at end of file
+});