diff --git a/lib/temp_dir.js b/lib/temp_dir.js
index 6543c2407..225059bbf 100644
--- a/lib/temp_dir.js
+++ b/lib/temp_dir.js
@@ -1,30 +1,31 @@
-var path = require('path')
-var fs = require('graceful-fs')
-var os = require('os')
-var rimraf = require('rimraf')
-var log = require('./logger').create('temp-dir')
+'use strict'
 
-var TEMP_DIR = os.tmpdir()
+const path = require('path')
+const fs = require('graceful-fs')
+const rimraf = require('rimraf')
+const log = require('./logger').create('temp-dir')
+
+const TEMP_DIR = require('os').tmpdir()
 
 module.exports = {
-  getPath: function (suffix) {
+  getPath (suffix) {
     return path.normalize(TEMP_DIR + suffix)
   },
 
-  create: function (path) {
-    log.debug('Creating temp dir at %s', path)
+  create (path) {
+    log.debug(`Creating temp dir at ${path}`)
 
     try {
       fs.mkdirSync(path)
     } catch (e) {
-      log.warn('Failed to create a temp dir at %s', path)
+      log.warn(`Failed to create a temp dir at ${path}`)
     }
 
     return path
   },
 
-  remove: function (path, done) {
-    log.debug('Cleaning temp dir %s', path)
+  remove (path, done) {
+    log.debug(`Cleaning temp dir ${path}`)
     rimraf(path, done)
   }
 }