diff --git a/phpBB/includes/functions_admin.php b/phpBB/includes/functions_admin.php
index d273b9fb3a..d9e445cff9 100644
--- a/phpBB/includes/functions_admin.php
+++ b/phpBB/includes/functions_admin.php
@@ -3040,38 +3040,29 @@ function tidy_database()
 */
 function add_permission_language()
 {
-	global $user, $phpEx;
+	global $user, $phpEx, $phpbb_extension_manager;
 
-	// First of all, our own file. We need to include it as the first file because it presets all relevant variables.
-	$user->add_lang('acp/permissions_phpbb');
+	// add permission language files from extensions
+	$finder = $phpbb_extension_manager->get_finder();
 
-	$files_to_add = array();
+	$lang_files = $finder
+		->prefix('permissions_')
+		->suffix(".$phpEx")
+		->core_path('language/' . $user->lang_name . '/')
+		->extension_directory('/language/' . $user->lang_name)
+		->find();
 
-	// Now search in acp and mods folder for permissions_ files.
-	foreach (array('acp/', 'mods/') as $path)
+	foreach ($lang_files as $lang_file => $ext_name)
 	{
-		$dh = @opendir($user->lang_path . $user->lang_name . '/' . $path);
-
-		if ($dh)
+		if ($ext_name === '/')
 		{
-			while (($file = readdir($dh)) !== false)
-			{
-				if ($file !== 'permissions_phpbb.' . $phpEx && strpos($file, 'permissions_') === 0 && substr($file, -(strlen($phpEx) + 1)) === '.' . $phpEx)
-				{
-					$files_to_add[] = $path . substr($file, 0, -(strlen($phpEx) + 1));
-				}
-			}
-			closedir($dh);
+			$user->add_lang($lang_file);
+		}
+		else
+		{
+			$user->add_lang_ext($ext_name, $lang_file);
 		}
 	}
-
-	if (!sizeof($files_to_add))
-	{
-		return false;
-	}
-
-	$user->add_lang($files_to_add);
-	return true;
 }
 
 /**
diff --git a/tests/functional/extension_permission_lang_test.php b/tests/functional/extension_permission_lang_test.php
new file mode 100644
index 0000000000..26ec4d28a1
--- /dev/null
+++ b/tests/functional/extension_permission_lang_test.php
@@ -0,0 +1,118 @@
+<?php
+/**
+*
+* @package testing
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+/**
+* @group functional
+*/
+class phpbb_functional_extension_permission_lang_test extends phpbb_functional_test_case
+{
+	protected $phpbb_extension_manager;
+
+	static private $helper;
+
+	static private $copied_files = array();
+
+	static protected $fixtures = array(
+		'foo/bar/language/en/',
+	);
+
+	/**
+	* This should only be called once before the tests are run.
+	* This is used to copy the fixtures to the phpBB install
+	*/
+	static public function setUpBeforeClass()
+	{
+		global $phpbb_root_path;
+		parent::setUpBeforeClass();
+
+		self::$helper = new phpbb_test_case_helpers(self);
+
+		self::$copied_files = array();
+
+		if (file_exists($phpbb_root_path . 'ext/'))
+		{
+			// First, move any extensions setup on the board to a temp directory
+			self::$copied_files = self::$helper->copy_dir($phpbb_root_path . 'ext/', $phpbb_root_path . 'store/temp_ext/');
+
+			// Then empty the ext/ directory on the board (for accurate test cases)
+			self::$helper->empty_dir($phpbb_root_path . 'ext/');
+		}
+
+		// Copy our ext/ files from the test case to the board
+		self::$copied_files = array_merge(self::$copied_files, self::$helper->copy_dir(dirname(__FILE__) . '/fixtures/ext/' . $fixture, $phpbb_root_path . 'ext/' . $fixture));
+	}
+
+	/**
+	* This should only be called once after the tests are run.
+	* This is used to remove the fixtures from the phpBB install
+	*/
+	static public function tearDownAfterClass()
+	{
+		global $phpbb_root_path;
+		
+		if (file_exists($phpbb_root_path . 'store/temp_ext/'))
+		{
+			// Copy back the board installed extensions from the temp directory
+			self::$helper->copy_dir($phpbb_root_path . 'store/temp_ext/', $phpbb_root_path . 'ext/');
+		}
+
+		// Remove all of the files we copied around (from board ext -> temp_ext, from test ext -> board ext)
+		self::$helper->remove_files(self::$copied_files);
+
+		if (file_exists($phpbb_root_path . 'store/temp_ext/'))
+		{
+			self::$helper->empty_dir($phpbb_root_path . 'store/temp_ext/');
+		}
+	}
+
+	public function setUp()
+	{
+		parent::setUp();
+		
+		$this->get_db();
+		
+		$acl_ary = array(
+			'auth_option'	=> 'u_foo',
+			'is_global'		=> 1,
+		);
+
+		$sql = 'INSERT INTO phpbb_acl_options ' . $this->db->sql_build_array('INSERT', $acl_ary);
+		$this->db->sql_query($sql);
+
+		$this->phpbb_extension_manager = $this->get_extension_manager();
+
+		$this->purge_cache();
+
+		$this->login();
+		$this->admin_login();
+		$this->add_lang('acp/permissions');
+	}
+
+	public function test_auto_include_permission_lang_from_extensions()
+	{
+		$this->phpbb_extension_manager->enable('foo/bar');
+
+		// User permissions
+		$crawler = $this->request('GET', 'adm/index.php?i=acp_permissions&icat=16&mode=setting_user_global&sid=' . $this->sid);
+		$this->assert_response_success();
+
+		// Select admin
+		$form = $crawler->selectButton($this->lang('SUBMIT'))->form();
+		$data = array('username[0]' => 'admin');
+		$form->setValues($data);
+		$crawler = $this->client->submit($form);
+		$this->assert_response_success();
+
+		// language from language/en/acp/permissions_phpbb.php
+		$this->assertContains('Can attach files', $crawler->filter('body')->text());
+
+		// language from ext/foo/bar/language/en/permissions_foo.php
+		$this->assertContains('Can view foo', $crawler->filter('body')->text());
+	}
+}
diff --git a/tests/functional/fixtures/ext/foo/bar/language/en/permissions_foo.php b/tests/functional/fixtures/ext/foo/bar/language/en/permissions_foo.php
new file mode 100644
index 0000000000..cd4b9a32d1
--- /dev/null
+++ b/tests/functional/fixtures/ext/foo/bar/language/en/permissions_foo.php
@@ -0,0 +1,6 @@
+<?php
+
+// Admin Permissions
+$lang = array_merge($lang, array(
+    'acl_u_foo'    => array('lang' => 'Can view foo', 'cat' => 'misc'),
+));