diff --git a/src/Symfony/Bundle/WebServerBundle/Resources/router.php b/src/Symfony/Bundle/WebServerBundle/Resources/router.php
index 187be0b836..a366b381aa 100644
--- a/src/Symfony/Bundle/WebServerBundle/Resources/router.php
+++ b/src/Symfony/Bundle/WebServerBundle/Resources/router.php
@@ -30,7 +30,7 @@ if (is_file($_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.$_SERVER['SCRIPT_NAME'
     return false;
 }
 
-$script = getenv('APP_FRONT_CONTROLLER') ?: 'index.php';
+$script = isset($_ENV['APP_FRONT_CONTROLLER']) ? $_ENV['APP_FRONT_CONTROLLER'] : 'index.php';
 
 $_SERVER = array_merge($_SERVER, $_ENV);
 $_SERVER['SCRIPT_FILENAME'] = $_SERVER['DOCUMENT_ROOT'].DIRECTORY_SEPARATOR.$script;
diff --git a/src/Symfony/Bundle/WebServerBundle/WebServer.php b/src/Symfony/Bundle/WebServerBundle/WebServer.php
index e3425ec8bb..4e5c001849 100644
--- a/src/Symfony/Bundle/WebServerBundle/WebServer.php
+++ b/src/Symfony/Bundle/WebServerBundle/WebServer.php
@@ -150,7 +150,7 @@ class WebServer
             throw new \RuntimeException('Unable to find the PHP binary.');
         }
 
-        $process = new Process(array($binary, '-S', $config->getAddress(), $config->getRouter()));
+        $process = new Process(array($binary, '-dvariables_order=EGPCS', '-S', $config->getAddress(), $config->getRouter()));
         $process->setWorkingDirectory($config->getDocumentRoot());
         $process->setTimeout(null);
 
diff --git a/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php b/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php
index 88ed375dd1..2615f16119 100644
--- a/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php
+++ b/src/Symfony/Bundle/WebServerBundle/WebServerConfig.php
@@ -32,7 +32,7 @@ class WebServerConfig
             throw new \InvalidArgumentException(sprintf('Unable to find the front controller under "%s" (none of these files exist: %s).', $documentRoot, implode(', ', $this->getFrontControllerFileNames($env))));
         }
 
-        putenv('APP_FRONT_CONTROLLER='.$file);
+        $_ENV['APP_FRONT_CONTROLLER'] = $file;
 
         $this->documentRoot = $documentRoot;
         $this->env = $env;
diff --git a/src/Symfony/Bundle/WebServerBundle/composer.json b/src/Symfony/Bundle/WebServerBundle/composer.json
index c48607bca4..6fa9d543de 100644
--- a/src/Symfony/Bundle/WebServerBundle/composer.json
+++ b/src/Symfony/Bundle/WebServerBundle/composer.json
@@ -19,7 +19,7 @@
         "php": "^5.5.9|>=7.0.8",
         "symfony/console": "~3.3",
         "symfony/http-kernel": "~3.3",
-        "symfony/process": "~3.3"
+        "symfony/process": "~3.3.14|^3.4.2"
     },
     "autoload": {
         "psr-4": { "Symfony\\Bundle\\WebServerBundle\\": "" },