diff --git a/bin/composer b/bin/composer
index 623d10b15..a2fba3ad0 100755
--- a/bin/composer
+++ b/bin/composer
@@ -8,6 +8,7 @@ use Composer\Installer;
 use Composer\Downloader;
 use Composer\Repository;
 use Composer\Package;
+use Composer\Json\JsonFile;
 use Composer\Console\Application as ComposerApplication;
 
 // initialize repository manager
@@ -29,10 +30,14 @@ $im->setInstaller('library', new Installer\LibraryInstaller('vendor', $dm, $rm->
 $loader  = new Package\Loader\JsonLoader();
 $package = $loader->load('composer.json');
 
+
+// init locker
+$locker = new Package\Locker(new JsonFile('composer.lock'), $rm);
+
 // initialize composer
 $composer = new Composer();
 $composer->setPackage($package);
-$composer->setPackageLock(new Package\PackageLock('composer.lock'));
+$composer->setLocker($locker);
 $composer->setRepositoryManager($rm);
 $composer->setDownloadManager($dm);
 $composer->setInstallationManager($im);
diff --git a/src/Composer/Command/InstallCommand.php b/src/Composer/Command/InstallCommand.php
index 8250ba23f..23dc89780 100644
--- a/src/Composer/Command/InstallCommand.php
+++ b/src/Composer/Command/InstallCommand.php
@@ -47,11 +47,11 @@ EOT
     {
         $composer = $this->getComposer();
 
-        if ($composer->getPackageLock()->isLocked()) {
+        if ($composer->getLocker()->isLocked()) {
             $output->writeln('<info>Found lockfile. Reading</info>');
 
             $installationManager = $composer->getInstallationManager();
-            foreach ($composer->getPackageLock()->getLockedPackages() as $package) {
+            foreach ($composer->getLocker()->getLockedPackages() as $package) {
                 if (!$installationManager->isPackageInstalled($package)) {
                     $operation = new Operation\InstallOperation($package, 'lock resolving');
                     $installationManager->execute($operation);
@@ -85,14 +85,10 @@ EOT
             $installationManager->execute($operation);
         }
 
-        // TODO implement lock
-        if (false) {
-            $composer->getPackageLock()->lock($localRepo->getPackages());
-            $output->writeln('> Locked');
-        }
+        $composer->getLocker()->lockPackages($localRepo->getPackages());
+        $output->writeln('> Locked');
 
         $localRepo->write();
-
         $output->writeln('> Done');
     }
 }
diff --git a/src/Composer/Composer.php b/src/Composer/Composer.php
index 9040043c3..be34af653 100644
--- a/src/Composer/Composer.php
+++ b/src/Composer/Composer.php
@@ -13,7 +13,7 @@
 namespace Composer;
 
 use Composer\Package\PackageInterface;
-use Composer\Package\PackageLock;
+use Composer\Package\Locker;
 use Composer\Repository\RepositoryManager;
 use Composer\Installer\InstallationManager;
 use Composer\Downloader\DownloadManager;
@@ -27,7 +27,7 @@ class Composer
     const VERSION = '1.0.0-DEV';
 
     private $package;
-    private $lock;
+    private $locker;
 
     private $repositoryManager;
     private $downloadManager;
@@ -43,14 +43,14 @@ class Composer
         return $this->package;
     }
 
-    public function setPackageLock($lock)
+    public function setLocker(Locker $locker)
     {
-        $this->lock = $lock;
+        $this->locker = $locker;
     }
 
-    public function getPackageLock()
+    public function getLocker()
     {
-        return $this->lock;
+        return $this->locker;
     }
 
     public function setRepositoryManager(RepositoryManager $manager)