diff --git a/scripts/filesize.js b/scripts/filesize.js
index ee9d3acca6..627a99f951 100755
--- a/scripts/filesize.js
+++ b/scripts/filesize.js
@@ -1,7 +1,7 @@
 #!/usr/bin/env node
 'use strict';
 
-const Flags = require('minimist')(process.argv.slice(2)),
+var Flags = require('minimist')(process.argv.slice(2)),
       Fs = require('fs'),
       Path = require('path'),
       GzipSize = require('gzip-size'),
@@ -16,9 +16,9 @@ let totalSize = 0,
     totalGzippedSize = 0,
     filePath = Path.resolve(process.cwd(), Flags.file);
 
-const rawSize = Fs.statSync(filePath).size;
+var rawSize = Fs.statSync(filePath).size;
 totalSize = PrettyBytes(rawSize);
-const rawGzippedSize = GzipSize.sync(Fs.readFileSync(filePath, 'utf8'));
+var rawGzippedSize = GzipSize.sync(Fs.readFileSync(filePath, 'utf8'));
 totalGzippedSize = PrettyBytes(rawGzippedSize);
 
 console.log('\n');
@@ -29,7 +29,7 @@ console.log('===================================================================
 console.log('\n');
 
 if (Flags.max) {
-  const max = Number(Flags.max) * 1000; // kb to bytes
+  var max = Number(Flags.max) * 1000; // kb to bytes
   if (max > totalSize) {
     process.exitCode = 1;
     console.log(Colors.red(`The total size of ${Path.basename(filePath)} exceeds ${PrettyBytes(max)}.`));
@@ -37,7 +37,7 @@ if (Flags.max) {
 }
 
 if (Flags.maxGzip) {
-  const maxGzip = Number(Flags.maxGzip) * 1000; // kb to bytes
+  var maxGzip = Number(Flags.maxGzip) * 1000; // kb to bytes
   if (rawGzippedSize > maxGzip) {
     process.exitCode = 1;
     console.log(Colors.red(`The total gzipped size of ${Path.basename(filePath)} exceeds ${PrettyBytes(maxGzip)}.`));