diff --git a/lib/bindings.js b/lib/bindings.js
index 35d1a76..c5c95b5 100644
--- a/lib/bindings.js
+++ b/lib/bindings.js
@@ -1,2 +1,3 @@
+'use strict';
 
 module.exports = require('../build/Release/canvas');
diff --git a/lib/canvas.js b/lib/canvas.js
index 587f59e..139c579 100644
--- a/lib/canvas.js
+++ b/lib/canvas.js
@@ -1,3 +1,4 @@
+'use strict';
 
 /*!
  * Canvas
@@ -66,7 +67,7 @@ exports.Image = Image;
 exports.ImageData = canvas.ImageData;
 
 if (FontFace) {
-  function Font(name, path, idx) {
+  var Font = function Font(name, path, idx) {
     this.name = name;
     this._faces = {};
 
diff --git a/lib/context2d.js b/lib/context2d.js
index 0941861..80d5e89 100644
--- a/lib/context2d.js
+++ b/lib/context2d.js
@@ -1,3 +1,5 @@
+'use strict';
+
 /*!
  * Canvas - Context2d
  * Copyright (c) 2010 LearnBoost <tj@learnboost.com>
diff --git a/lib/image.js b/lib/image.js
index 558472b..932ad90 100644
--- a/lib/image.js
+++ b/lib/image.js
@@ -1,3 +1,4 @@
+'use strict';
 
 /*!
  * Canvas - Image
@@ -32,9 +33,9 @@ Image.prototype.__defineSetter__('src', function(val){
 
 /**
  * Src getter.
- * 
+ *
  * TODO: return buffer
- * 
+ *
  * @api public
  */
 
diff --git a/lib/jpegstream.js b/lib/jpegstream.js
index 95e84ef..24ca6f3 100644
--- a/lib/jpegstream.js
+++ b/lib/jpegstream.js
@@ -1,3 +1,4 @@
+'use strict';
 
 /*!
  * Canvas - JPEGStream
diff --git a/lib/pngstream.js b/lib/pngstream.js
index 38e08cd..8a538d0 100644
--- a/lib/pngstream.js
+++ b/lib/pngstream.js
@@ -1,3 +1,4 @@
+'use strict';
 
 /*!
  * Canvas - PNGStream
@@ -57,4 +58,4 @@ var PNGStream = module.exports = function PNGStream(canvas, sync) {
  * Inherit from `EventEmitter`.
  */
 
-PNGStream.prototype.__proto__ = Stream.prototype;
\ No newline at end of file
+PNGStream.prototype.__proto__ = Stream.prototype;