diff --git a/src/Composer/Installers/DrupalInstaller.php b/src/Composer/Installers/DrupalInstaller.php
index 193e6008..76014e44 100644
--- a/src/Composer/Installers/DrupalInstaller.php
+++ b/src/Composer/Installers/DrupalInstaller.php
@@ -1,12 +1,134 @@
 <?php
 namespace Composer\Installers;
 
+/**
+ * The Drupal Installer for Composer Installers.
+ *
+ * This locates Drupal's root directory, and installs into sites/all if
+ * the path is available. Note that much of this was adopted from Drush.
+ *
+ * @link http://drupal.org/project/drush
+ */
 class DrupalInstaller extends BaseInstaller
 {
     protected $locations = array(
-        'module'    => 'modules/{$name}/',
-        'theme'     => 'themes/{$name}/',
-        'profile'   => 'profiles/{$name}/',
-        'drush'     => 'drush/{$name}/',
+        'module'    => '{$root}/modules/{$name}/',
+        'theme'     => '{$root}/themes/{$name}/',
+        'profile'   => '{$root}/profiles/{$name}/',
+        'drush'     => '{$root}/drush/{$name}/',
     );
+
+    /**
+     * {@inheritDoc}
+     */
+    public function inflectPackageVars($vars)
+    {
+        // Find Drupal's root directory.
+        $root = $this->locateDrupalRoot();
+        if ($root) {
+            // If we are installing on Drupal 5, 6 or 7, use "sites/all".
+            if (version_compare($this->drupalMajorVersion($root), '8', '<')) {
+                $root .= '/sites/all';
+            }
+        }
+        else {
+            // If it's not a valid directory, then use the current directory.
+            $root = '.';
+        }
+
+        // Inject Drupal's root directory into the variables array.
+        $vars['root'] = $root;
+
+        return $vars;
+    }
+
+    /**
+     * Checks whether given path qualifies as a Drupal root.
+     *
+     * @param $path
+     *   The relative path to common.inc (varies by Drupal version), or FALSE if
+     *   not a Drupal root.
+     */
+    protected function validDrupalRoot($path) {
+        if (!empty($path) && is_dir($path)) {
+          $candidates = array('includes/common.inc', 'core/includes/common.inc');
+          foreach ($candidates as $candidate) {
+            if (file_exists($path . '/' . $candidate)) {
+              return $candidate;
+            }
+          }
+        }
+
+        return false;
+    }
+
+    /**
+     * Exhaustive depth-first search to try and locate the Drupal root directory.
+     */
+    protected function locateDrupalRoot($path = '')
+    {
+        $path = empty($path) ? getcwd() : $path;
+        do {
+            if ($this->validDrupalRoot($path)) {
+                return $path;
+            }
+        }
+        while ($path = dirname($path) && $path != DIRECTORY_SEPARATOR);
+
+        return false;
+    }
+
+    /**
+    * Return the user's home directory.
+    */
+    protected function serverHome() {
+        $home = getenv('HOME');
+
+        if (empty($home)) {
+            if (!empty($_SERVER['HOMEDRIVE']) && !empty($_SERVER['HOMEPATH'])) {
+                // On a Windows server.
+                $home = $_SERVER['HOMEDRIVE'] . $_SERVER['HOMEPATH'];
+            }
+        }
+
+        return empty($home) ? NULL : $home;
+    }
+
+    /**
+     * Retrieves Drupal version.
+     *
+     * @return string A version string similar to 7.22-dev.
+     */
+    protected function drupalVersion($drupal_root = null) {
+        if (($drupal_root != null) || ($drupal_root = $this->locateDrupalRoot())) {
+            // Drupal 7 stores VERSION in includes/bootstrap.inc, while Drupal 8
+            // uses core/includes/bootstrap.inc.
+            $version_constant_paths = array('/modules/system/system.module', '/includes/bootstrap.inc', '/core/includes/bootstrap.inc');
+            foreach ($version_constant_paths as $path) {
+                if (file_exists($drupal_root . $path)) {
+                    require_once $drupal_root . $path;
+                }
+            }
+
+            if (defined('VERSION')) {
+               return VERSION;
+            }
+        }
+    }
+
+    /**
+     * Retrieves Drupal's major version number.
+     */
+    protected function drupalMajorVersion($drupal_root = null)
+    {
+        $major_version = false;
+        if ($version = $this->drupalVersion($drupal_root)) {
+            $version_parts = explode('.', $version);
+            if (is_numeric($version_parts[0])) {
+                $major_version = (integer) $version_parts[0];
+            }
+        }
+
+        return $major_version;
+    }
 }
diff --git a/tests/Composer/Installers/Test/InstallerTest.php b/tests/Composer/Installers/Test/InstallerTest.php
index eb83f86e..a5db111c 100644
--- a/tests/Composer/Installers/Test/InstallerTest.php
+++ b/tests/Composer/Installers/Test/InstallerTest.php
@@ -137,10 +137,10 @@ public function dataForTestInstallPath()
             array('cakephp-plugin', 'Plugin/Ftp/', 'shama/ftp'),
             array('codeigniter-library', 'libraries/my_package/', 'shama/my_package'),
             array('codeigniter-module', 'modules/my_package/', 'shama/my_package'),
-            array('drupal-module', 'modules/my_module/', 'shama/my_module'),
-            array('drupal-theme', 'themes/my_module/', 'shama/my_module'),
-            array('drupal-profile', 'profiles/my_module/', 'shama/my_module'),
-            array('drupal-drush', 'drush/my_module/', 'shama/my_module'),
+            array('drupal-module', './modules/my_module/', 'shama/my_module'),
+            array('drupal-theme', './themes/my_module/', 'shama/my_module'),
+            array('drupal-profile', './profiles/my_module/', 'shama/my_module'),
+            array('drupal-drush', './drush/my_module/', 'shama/my_module'),
             array('fuel-module', 'fuel/app/modules/module/', 'fuel/module'),
             array('fuel-package', 'fuel/packages/orm/', 'fuel/orm'),
             array('joomla-plugin', 'plugins/my_plugin/', 'shama/my_plugin'),