diff --git a/src/Composer/Installer/LibraryInstaller.php b/src/Composer/Installer/LibraryInstaller.php
index 64b300c35..cb3808295 100644
--- a/src/Composer/Installer/LibraryInstaller.php
+++ b/src/Composer/Installer/LibraryInstaller.php
@@ -43,7 +43,7 @@ class LibraryInstaller implements InstallerInterface
      * @param string      $type
      * @param Filesystem  $filesystem
      */
-    public function __construct(IOInterface $io, Composer $composer, $type = 'library', $filesystem = null)
+    public function __construct(IOInterface $io, Composer $composer, $type = 'library', Filesystem $filesystem = null)
     {
         $this->composer = $composer;
         $this->downloadManager = $composer->getDownloadManager();
diff --git a/tests/Composer/Test/Plugin/PluginInstallerTest.php b/tests/Composer/Test/Plugin/PluginInstallerTest.php
index 79e141530..2502dded9 100644
--- a/tests/Composer/Test/Plugin/PluginInstallerTest.php
+++ b/tests/Composer/Test/Plugin/PluginInstallerTest.php
@@ -89,7 +89,8 @@ class PluginInstallerTest extends \PHPUnit_Framework_TestCase
         ));
     }
 
-    protected function tearDown() {
+    protected function tearDown()
+    {
         $filesystem = new Filesystem();
         $filesystem->removeDirectory($this->directory);
     }