diff --git a/lib/system/has-flag.js b/lib/system/has-flag.js
index 541c4e1..c9698f8 100644
--- a/lib/system/has-flag.js
+++ b/lib/system/has-flag.js
@@ -11,10 +11,10 @@ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLI
 */
 
 'use strict';
-module.exports = (flag, argv) => {
+module.exports = function(flag, argv) {
 	argv = argv || process.argv;
-	const prefix = flag.startsWith('-') ? '' : (flag.length === 1 ? '-' : '--');
-	const pos = argv.indexOf(prefix + flag);
-	const terminatorPos = argv.indexOf('--');
-	return pos !== -1 && (terminatorPos === -1 ? true : pos < terminatorPos);
+	var prefix = flag.startsWith('-') ? '' : (flag.length === 1 ? '-' : '--');
+	var pos = argv.indexOf(prefix + flag);
+	var terminatorPos = argv.indexOf('--');
+	var pos !== -1 && (terminatorPos === -1 ? true : pos < terminatorPos);
 };