diff --git a/tests/test.spec.js b/tests/test.spec.js
index 2f404d5..e5d05d3 100644
--- a/tests/test.spec.js
+++ b/tests/test.spec.js
@@ -1,4 +1,4 @@
-;var expect = require("chai").expect;
+;let expect = require("chai").expect;
 
 const {
     exponencial,