diff --git a/lib/Minify.php b/lib/Minify.php
index 1fe79a9..ba5ac4d 100644
--- a/lib/Minify.php
+++ b/lib/Minify.php
@@ -56,6 +56,11 @@ class Minify {
      */
     protected $controller = null;
 
+    /**
+     * @var Minify_Env
+     */
+    protected $env;
+
     /**
      * @var Minify_SourceInterface[]
      */
@@ -218,6 +223,8 @@ class Minify {
      */
     public function serve(Minify_ControllerInterface $controller, $options = array())
     {
+        $this->env = $controller->getEnv();
+
         $options = array_merge($this->getDefaultOptions(), $options);
 
         $config = $controller->createConfiguration($options);
@@ -499,7 +506,7 @@ class Minify {
     protected function setupUriRewrites()
     {
         foreach($this->sources as $key => $source) {
-            $file = $source->getFilePath();
+            $file = $this->env->normalizePath($source->getFilePath());
             $minifyOptions = $source->getMinifierOptions();
 
             if ($file
diff --git a/lib/Minify/App.php b/lib/Minify/App.php
index 014f149..d39a639 100644
--- a/lib/Minify/App.php
+++ b/lib/Minify/App.php
@@ -104,7 +104,7 @@ class App extends Container {
             if (empty($config->documentRoot)) {
                 return $app->env->getDocRoot();
             }
-            return rtrim($config->documentRoot, '/\\');
+            return $app->env->normalizePath($config->documentRoot);
         };
 
         $this->env = function (App $app) {
diff --git a/lib/Minify/Controller/Base.php b/lib/Minify/Controller/Base.php
index aa83e36..e95e6e9 100644
--- a/lib/Minify/Controller/Base.php
+++ b/lib/Minify/Controller/Base.php
@@ -69,4 +69,12 @@ abstract class Minify_Controller_Base implements Minify_ControllerInterface {
         trigger_error(__METHOD__ . ' is deprecated in Minify 3.0.', E_USER_DEPRECATED);
         $this->logger->info($msg);
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getEnv()
+    {
+        return $this->env;
+    }
 }
diff --git a/lib/Minify/ControllerInterface.php b/lib/Minify/ControllerInterface.php
index 3828875..ebd71a4 100644
--- a/lib/Minify/ControllerInterface.php
+++ b/lib/Minify/ControllerInterface.php
@@ -12,4 +12,11 @@ interface Minify_ControllerInterface {
      * @return Minify_ServeConfiguration
      */
     public function createConfiguration(array $options);
+
+    /**
+     * Get the Env component
+     *
+     * @return Minify_Env
+     */
+    public function getEnv();
 }
\ No newline at end of file
diff --git a/lib/Minify/Env.php b/lib/Minify/Env.php
index e6718f6..12e132d 100644
--- a/lib/Minify/Env.php
+++ b/lib/Minify/Env.php
@@ -33,6 +33,7 @@ class Minify_Env {
         } else {
             $this->server['DOCUMENT_ROOT'] = rtrim($this->server['DOCUMENT_ROOT'], '/\\');
         }
+        $this->server['DOCUMENT_ROOT'] = $this->normalizePath($this->server['DOCUMENT_ROOT']);
         $this->get = $options['get'];
         $this->post = $options['post'];
         $this->cookie = $options['cookie'];
@@ -76,6 +77,29 @@ class Minify_Env {
         return isset($this->post[$key]) ? $this->post[$key] : $default;
     }
 
+    /**
+     * turn windows-style slashes into unix-style,
+     * remove trailing slash
+     * and lowercase drive letter
+     *
+     * @param string $path absolute path
+     *
+     * @return string
+     */
+    public function normalizePath($path)
+    {
+        $realpath = realpath($path);
+        if ($realpath) {
+            $path = $realpath;
+        }
+        $path = str_replace('\\', '/', $path);
+        $path = rtrim($path, '/');
+        if (substr($path, 1, 1) === ':') {
+            $path = lcfirst($path);
+        }
+        return $path;
+    }
+
     protected $server = null;
     protected $get = null;
     protected $post = null;
diff --git a/lib/Minify/Source/Factory.php b/lib/Minify/Source/Factory.php
index 476e798..7033179 100644
--- a/lib/Minify/Source/Factory.php
+++ b/lib/Minify/Source/Factory.php
@@ -110,20 +110,6 @@ class Minify_Source_Factory {
         return $realpath;
     }
 
-    /**
-     * turn windows-style slashes into unix-style,
-     * remove trailing slash
-     * and lowercase drive letter
-     *
-     * @param string $path absolute path
-     *
-     * @return string
-     */
-    public function getNormalizedPath($path)
-    {
-        return lcfirst(rtrim(str_replace('\\', '/', $path), '/'));
-    }
-
     /**
      * @param mixed $spec
      *
@@ -159,8 +145,9 @@ class Minify_Source_Factory {
         if ($this->options['checkAllowDirs']) {
             $allowDirs = (array)$this->options['allowDirs'];
             $inAllowedDir = false;
+            $filePath = $this->env->normalizePath($spec['filepath']);
             foreach ($allowDirs as $allowDir) {
-                if (strpos($this->getNormalizedPath($spec['filepath']), $this->getNormalizedPath($allowDir)) === 0) {
+                if (strpos($filePath, $this->env->normalizePath($allowDir)) === 0) {
                     $inAllowedDir = true;
                 }
             }