diff --git a/src/fs-watcher.js b/src/fs-watcher.js
index e236bcb..c7e7f1b 100644
--- a/src/fs-watcher.js
+++ b/src/fs-watcher.js
@@ -1,6 +1,8 @@
-var EventEmitter = require('../lib/eventemitter.js');
-var Path = require('./path.js');
-var Intercom = require('../lib/intercom.js');
+'using strict';
+
+const EventEmitter = require('../lib/eventemitter.js');
+const Path = require('./path.js');
+const Intercom = require('../lib/intercom.js');
 
 /**
  * FSWatcher based on node.js' FSWatcher
@@ -8,10 +10,10 @@ var Intercom = require('../lib/intercom.js');
  */
 function FSWatcher() {
   EventEmitter.call(this);
-  var self = this;
-  var recursive = false;
-  var recursivePathPrefix;
-  var filename;
+  const self = this;
+  let recursive = false;
+  let recursivePathPrefix;
+  let filename;
 
   function onchange(path) {
     // Watch for exact filename, or parent path when recursive is true.
@@ -46,12 +48,12 @@ function FSWatcher() {
       recursivePathPrefix = filename === '/' ? '/' : filename + '/';
     }
 
-    var intercom = Intercom.getInstance();
+    const intercom = Intercom.getInstance();
     intercom.on('change', onchange);
   };
 
   self.close = function() {
-    var intercom = Intercom.getInstance();
+    const intercom = Intercom.getInstance();
     intercom.off('change', onchange);
     self.removeAllListeners('change');
   };