diff --git a/src/Symfony/Installer/DownloadCommand.php b/src/Symfony/Installer/DownloadCommand.php
index 80083bd..b5f3371 100644
--- a/src/Symfony/Installer/DownloadCommand.php
+++ b/src/Symfony/Installer/DownloadCommand.php
@@ -42,6 +42,7 @@ abstract class DownloadCommand extends Command
     /**
      * Returns the type of the downloaded application in a human readable format.
      * It's mainly used to display readable error messages.
+     *
      * @return string
      */
     abstract protected function getDownloadedApplicationType();
@@ -112,7 +113,7 @@ protected function download()
             $progressBar->setProgress($downloaded);
         };
 
-        $client = new Client();
+        $client = $this->getGuzzleClient();
         $client->getEmitter()->attach(new Progress(null, $downloadCallback));
 
         // store the file in a temporary hidden directory with a random name
@@ -149,6 +150,25 @@ protected function download()
         return $this;
     }
 
+    /**
+     * Returns the Guzzle client configured according to the system environment
+     * (e.g. it takes into account whether it should use a proxy server or not).
+     *
+     * @return Client
+     */
+    protected function getGuzzleClient()
+    {
+        $options = array();
+
+        // check if the client must use a proxy server
+        if (!empty($_SERVER['HTTP_PROXY']) || !empty($_SERVER['http_proxy'])) {
+            $proxy = !empty($_SERVER['http_proxy']) ? $_SERVER['http_proxy'] : $_SERVER['HTTP_PROXY'];
+            $options['proxy'] = $proxy;
+        }
+
+        return new Client($options);
+    }
+
     /**
      * Extracts the compressed Symfony file (ZIP or TGZ) using the
      * native operating system commands if available or PHP code otherwise.
@@ -207,7 +227,7 @@ protected function extract()
     }
 
     /**
-     * Checks if environment meets symfony requirements
+     * Checks if environment meets symfony requirements.
      *
      * @return Command
      */
@@ -298,7 +318,7 @@ protected function getErrorMessage(\Requirement $requirement, $lineSize = 70)
     }
 
     /**
-     * Generates a good random value for Symfony's 'secret' option
+     * Generates a good random value for Symfony's 'secret' option.
      *
      * @return string
      */
@@ -340,7 +360,8 @@ protected function getExecutedCommand()
     /**
      * Checks whether the given directory is empty or not.
      *
-     * @param  string $dir the path of the directory to check
+     * @param string $dir the path of the directory to check
+     *
      * @return bool
      */
     protected function isEmptyDirectory($dir)
diff --git a/src/Symfony/Installer/NewCommand.php b/src/Symfony/Installer/NewCommand.php
index b62e4d6..b7154de 100644
--- a/src/Symfony/Installer/NewCommand.php
+++ b/src/Symfony/Installer/NewCommand.php
@@ -11,7 +11,6 @@
 
 namespace Symfony\Installer;
 
-use GuzzleHttp\Client;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
@@ -130,7 +129,7 @@ protected function checkSymfonyVersionIsInstallable()
         if (preg_match('/^2\.\d$/', $this->version)) {
             // Check if we have a minor version in order to retrieve the last patch from symfony.com
 
-            $client = new Client();
+            $client = $this->getGuzzleClient();
             $versionsList = $client->get('http://symfony.com/versions.json')->json();
 
             if ($versionsList && isset($versionsList[$this->version])) {