diff --git a/src/BinCommand.php b/src/BinCommand.php
index 5a299b1..93acaf4 100644
--- a/src/BinCommand.php
+++ b/src/BinCommand.php
@@ -102,6 +102,12 @@ private function executeInNamespace(ComposerApplication $application, $namespace
         }
 
         $this->chdir($namespace);
+
+        // some plugins require access to composer file e.g. Symfony Flex
+        if (!file_exists(Factory::getComposerFile())) {
+            file_put_contents(Factory::getComposerFile(), '{}');
+        }
+        
         $input = new StringInput((string) $input . ' --working-dir=.');
 
         $this->getIO()->writeError('<info>Run with <comment>' . $input->__toString() . '</comment></info>', true, IOInterface::VERBOSE);
diff --git a/tests/Fixtures/MyTestCommand.php b/tests/Fixtures/MyTestCommand.php
index ee8ffce..f2f6bc6 100644
--- a/tests/Fixtures/MyTestCommand.php
+++ b/tests/Fixtures/MyTestCommand.php
@@ -27,12 +27,11 @@ public function __construct(\PHPUnit_Framework_Assert $assert)
 
     public function execute(InputInterface $input, OutputInterface $output)
     {
-        // make sure the proxy command didn't instantiate Composer
-        $this->assert->assertNull($this->getComposer(false));
-        $this->assert->assertNull($this->getApplication()->getComposer(false));
-
-        // put a dummy composer.json to be able to create Composer
-        file_put_contents(getcwd().'/composer.json', '{}');
+        $this->assert->assertInstanceOf(
+            '\Composer\Composer',
+            $this->getComposer(),
+            "Some plugins may require access to composer file e.g. Symfony Flex"
+        );
 
         $factory = Factory::create(new NullIO());
         $config = $factory->getConfig();