diff --git a/bin/composer b/bin/composer
index 4cf1eec23..d6ee9cf51 100755
--- a/bin/composer
+++ b/bin/composer
@@ -13,9 +13,7 @@ use Composer\Console\Application as ComposerApplication;
 
 // initialize repository manager
 $rm = new Repository\RepositoryManager();
-$rm->setLocalRepository(new Repository\PlatformRepository(
-    new Repository\FilesystemRepository(new JsonFile('.composer/installed.json'))
-));
+$rm->setLocalRepository(new Repository\FilesystemRepository(new JsonFile('.composer/installed.json')));
 $rm->setRepository('Packagist', new Repository\ComposerRepository('http://packagist.org'));
 
 // initialize download manager
@@ -33,7 +31,6 @@ $im->setInstaller('symfony-bundle', new Installer\LibraryInstaller('vendor/bundl
 $loader  = new Package\Loader\JsonLoader();
 $package = $loader->load(new JsonFile('composer.json'));
 
-
 // init locker
 $locker = new Package\Locker(new JsonFile('composer.lock'), $rm);
 
diff --git a/src/Composer/Command/InstallCommand.php b/src/Composer/Command/InstallCommand.php
index b8718c50a..c9578a48b 100644
--- a/src/Composer/Command/InstallCommand.php
+++ b/src/Composer/Command/InstallCommand.php
@@ -74,8 +74,9 @@ EOT
         // prepare solver
         $installationManager = $composer->getInstallationManager();
         $localRepo           = $composer->getRepositoryManager()->getLocalRepository();
+        $installedRepo       = new Repository\PlatformRepository($localRepo);
         $policy              = new DependencyResolver\DefaultPolicy();
-        $solver              = new DependencyResolver\Solver($policy, $pool, $localRepo);
+        $solver              = new DependencyResolver\Solver($policy, $pool, $installedRepo);
 
         // solve dependencies
         $operations = $solver->solve($request);
@@ -111,8 +112,6 @@ EOT
         $localRepo->write();
 
         $output->writeln('> Generating autoload.php');
-        $localRepo = new \Composer\Repository\FilesystemRepository(
-            new \Composer\Json\JsonFile('.composer/installed.json'));
         $generator = new AutoloadGenerator($localRepo, $composer->getPackage(), $installationManager);
         $generator->dump('.composer/autoload.php');
 
diff --git a/src/Composer/Package/Locker.php b/src/Composer/Package/Locker.php
index 9e9631589..3d069af80 100644
--- a/src/Composer/Package/Locker.php
+++ b/src/Composer/Package/Locker.php
@@ -88,10 +88,6 @@ class Locker
             $name    = $package->getName();
             $version = $package->getVersion();
 
-            if ('php' === $name || preg_match('{^ext-[a-z0-9_-]+$}', $name)) {
-                continue;
-            }
-
             if (!$name || !$version) {
                 throw new \LogicException(sprintf(
                     'Package "%s" has no version or name and can not be locked', $package
diff --git a/src/Composer/Repository/PlatformRepository.php b/src/Composer/Repository/PlatformRepository.php
index dd3b4bcce..cc51a6061 100644
--- a/src/Composer/Repository/PlatformRepository.php
+++ b/src/Composer/Repository/PlatformRepository.php
@@ -20,11 +20,11 @@ use Composer\Package\Version\VersionParser;
 /**
  * @author Jordi Boggiano <j.boggiano@seld.be>
  */
-class PlatformRepository extends ArrayRepository implements WritableRepositoryInterface
+class PlatformRepository extends ArrayRepository
 {
     private $localRepository;
 
-    public function __construct(WritableRepositoryInterface $localRepository)
+    public function __construct(RepositoryInterface $localRepository)
     {
         $this->localRepository = $localRepository;
     }
@@ -65,28 +65,4 @@ class PlatformRepository extends ArrayRepository implements WritableRepositoryIn
     {
         return array_merge(parent::getPackages(), $this->localRepository->getPackages());
     }
-
-    /**
-     * {@inheritDoc}
-     */
-    public function addPackage(PackageInterface $package)
-    {
-        $this->localRepository->addPackage($package);
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    public function removePackage(PackageInterface $package)
-    {
-        $this->localRepository->removePackage($package);
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    public function write()
-    {
-        $this->localRepository->write();
-    }
 }