diff --git a/src/Composer/Console/Application.php b/src/Composer/Console/Application.php
index 64166a982..3a784f8a8 100644
--- a/src/Composer/Console/Application.php
+++ b/src/Composer/Console/Application.php
@@ -153,7 +153,10 @@ class Application extends BaseApplication
         $this->disablePluginsByDefault = $input->hasParameterOption('--no-plugins');
         $this->disableScriptsByDefault = $input->hasParameterOption('--no-scripts');
 
-        $stdin = defined('STDIN') ? STDIN : fopen('php://stdin', 'r');
+        static $stdin = null;
+        if (null === $stdin) {
+            $stdin = defined('STDIN') ? STDIN : fopen('php://stdin', 'r');
+        }
         if (Platform::getEnv('COMPOSER_TESTS_ARE_RUNNING') !== '1' && (Platform::getEnv('COMPOSER_NO_INTERACTION') || $stdin === false || !Platform::isTty($stdin))) {
             $input->setInteractive(false);
         }