diff --git a/lib/Minify.php b/lib/Minify.php
index df6a8ea..224fd9a 100644
--- a/lib/Minify.php
+++ b/lib/Minify.php
@@ -45,14 +45,14 @@ class Minify
      *
      * @var Minify_CacheInterface
      */
-    private $cache = null;
+    private $cache;
 
     /**
      * Active controller for current request
      *
      * @var Minify_Controller_Base
      */
-    protected $controller = null;
+    protected $controller;
 
     /**
      * @var Minify_Env
@@ -74,12 +74,12 @@ class Minify
      *
      * @var array
      */
-    protected $options = null;
+    protected $options;
 
     /**
      * @var LoggerInterface|null
      */
-    protected $logger = null;
+    protected $logger;
 
     /**
      * @param Minify_CacheInterface $cache
diff --git a/lib/Minify/ClosureCompiler.php b/lib/Minify/ClosureCompiler.php
index 26cbc67..238bfe3 100644
--- a/lib/Minify/ClosureCompiler.php
+++ b/lib/Minify/ClosureCompiler.php
@@ -38,14 +38,14 @@ class Minify_ClosureCompiler
      *
      * @var string
      */
-    public static $jarFile = null;
+    public static $jarFile;
 
     /**
      * Writable temp directory. This must be set before calling minifyJs().
      *
      * @var string
      */
-    public static $tempDir = null;
+    public static $tempDir;
 
     /**
      * Filepath of "java" executable (may be needed if not in shell's PATH)
diff --git a/lib/Minify/Env.php b/lib/Minify/Env.php
index 25490bc..84e7a0e 100644
--- a/lib/Minify/Env.php
+++ b/lib/Minify/Env.php
@@ -102,10 +102,10 @@ class Minify_Env
         return $path;
     }
 
-    protected $server = null;
-    protected $get = null;
-    protected $post = null;
-    protected $cookie = null;
+    protected $server;
+    protected $get;
+    protected $post;
+    protected $cookie;
 
     /**
      * Compute $_SERVER['DOCUMENT_ROOT'] for IIS using SCRIPT_FILENAME and SCRIPT_NAME.
diff --git a/lib/Minify/HTML.php b/lib/Minify/HTML.php
index c3453f5..df648e1 100644
--- a/lib/Minify/HTML.php
+++ b/lib/Minify/HTML.php
@@ -177,11 +177,11 @@ class Minify_HTML
         return $placeholder;
     }
 
-    protected $_isXhtml = null;
-    protected $_replacementHash = null;
+    protected $_isXhtml;
+    protected $_replacementHash;
     protected $_placeholders = array();
-    protected $_cssMinifier = null;
-    protected $_jsMinifier = null;
+    protected $_cssMinifier;
+    protected $_jsMinifier;
 
     protected function _removePreCB($m)
     {
diff --git a/lib/Minify/ImportProcessor.php b/lib/Minify/ImportProcessor.php
index 4191f32..f1000d2 100644
--- a/lib/Minify/ImportProcessor.php
+++ b/lib/Minify/ImportProcessor.php
@@ -32,15 +32,15 @@ class Minify_ImportProcessor
     }
 
     // allows callback funcs to know the current directory
-    private $_currentDir = null;
+    private $_currentDir;
 
     // allows callback funcs to know the directory of the file that inherits this one
-    private $_previewsDir = null;
+    private $_previewsDir;
 
     // allows _importCB to write the fetched content back to the obj
     private $_importedContent = '';
 
-    private static $_isCss = null;
+    private static $_isCss;
 
     /**
      * @param String $currentDir
diff --git a/lib/Minify/Source.php b/lib/Minify/Source.php
index 94eb6dd..d7f83ef 100644
--- a/lib/Minify/Source.php
+++ b/lib/Minify/Source.php
@@ -19,12 +19,12 @@ class Minify_Source implements Minify_SourceInterface
     /**
      * @var int time of last modification
      */
-    protected $lastModified = null;
+    protected $lastModified;
 
     /**
      * @var callback minifier function specifically for this source.
      */
-    protected $minifier = null;
+    protected $minifier;
 
     /**
      * @var array minification options specific to this source.
@@ -34,27 +34,27 @@ class Minify_Source implements Minify_SourceInterface
     /**
      * @var string full path of file
      */
-    protected $filepath = null;
+    protected $filepath;
 
     /**
      * @var string HTTP Content Type (Minify requires one of the constants Minify::TYPE_*)
      */
-    protected $contentType = null;
+    protected $contentType;
 
     /**
      * @var string
      */
-    protected $content = null;
+    protected $content;
 
     /**
      * @var callable
      */
-    protected $getContentFunc = null;
+    protected $getContentFunc;
 
     /**
      * @var string
      */
-    protected $id = null;
+    protected $id;
 
     /**
      * Create a Minify_Source
diff --git a/lib/Minify/YUICompressor.php b/lib/Minify/YUICompressor.php
index 4c3c53b..a45f572 100644
--- a/lib/Minify/YUICompressor.php
+++ b/lib/Minify/YUICompressor.php
@@ -38,7 +38,7 @@ class Minify_YUICompressor
      *
      * @var string
      */
-    public static $jarFile = null;
+    public static $jarFile;
 
     /**
      * Writable temp directory. This must be set before calling minifyJs()
@@ -46,7 +46,7 @@ class Minify_YUICompressor
      *
      * @var string
      */
-    public static $tempDir = null;
+    public static $tempDir;
 
     /**
      * Filepath of "java" executable (may be needed if not in shell's PATH)