diff --git a/phpBB/includes/acp/acp_language.php b/phpBB/includes/acp/acp_language.php
index 31fa428e36..defc811e8b 100644
--- a/phpBB/includes/acp/acp_language.php
+++ b/phpBB/includes/acp/acp_language.php
@@ -19,48 +19,117 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
+use phpbb\config\config;
+use phpbb\db\driver\driver_interface;
+use phpbb\event\dispatcher;
+use phpbb\language\language;
+use phpbb\language\language_file_helper;
+use phpbb\log\log_interface;
+use phpbb\request\request_interface;
+use phpbb\template\template;
+use phpbb\user;
+
 class acp_language
 {
 	var $u_action;
 	var $main_files;
-	var $language_header = '';
-	var $lang_header = '';
 
 	var $language_file = '';
 	var $language_directory = '';
 
-	function main($id, $mode)
+	/** @var config Config class */
+	protected $config;
+
+	/** @var driver_interface DBAL driver */
+	protected $db;
+
+	/** @var dispatcher Event dispatcher */
+	protected $dispatcher;
+
+	/** @var language Language class */
+	protected $language;
+
+	/** @var language_file_helper Language file helper */
+	protected $language_helper;
+
+	/** @var log_interface Logging class */
+	protected $log;
+
+	/** @var request_interface */
+	protected $request;
+
+	/** @var template Template class */
+	protected $template;
+
+	/** @var user User class */
+	protected $user;
+
+	/** @var string phpBB root path */
+	protected $phpbb_root_path;
+
+	/** @var string PHP file extension */
+	protected $php_ext;
+
+	/** @var string Page title */
+	public $page_title = 'ACP_LANGUAGE_PACKS';
+
+	/** @var string Template name */
+	public $tpl_name = 'acp_language';
+
+	/**
+	 * acp_language constructor
+	 */
+	public function __construct()
 	{
 		global $config, $db, $user, $template, $phpbb_log, $phpbb_container;
 		global $phpbb_root_path, $phpEx, $request, $phpbb_dispatcher;
 
+		$this->config = $config;
+		$this->db = $db;
+		$this->dispatcher = $phpbb_dispatcher;
+		$this->language = $phpbb_container->get('language');
+		$this->language_helper = $phpbb_container->get('language.helper.language_file');
+		$this->log = $phpbb_log;
+		$this->request = $request;
+		$this->template = $template;
+		$this->user = $user;
+		$this->phpbb_root_path = $phpbb_root_path;
+		$this->php_ext = $phpEx;
+	}
+
+	/**
+	 * Main handler for acp_language
+	 *
+	 * @param int $id Module ID
+	 * @param string $mode Module mode
+	 */
+	public function main($id, $mode)
+	{
 		if (!function_exists('validate_language_iso_name'))
 		{
-			include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+			include($this->phpbb_root_path . 'includes/functions_user.' . $this->php_ext);
 		}
 
 		// Check and set some common vars
-		$action		= (isset($_POST['update_details'])) ? 'update_details' : '';
-		$action		= (isset($_POST['remove_store'])) ? 'details' : $action;
+		$action		= $this->request->is_set_post('update_details') ? 'update_details' : '';
+		$action		= $this->request->is_set_post('remove_store') ? 'details' : $action;
 
-		$submit = (empty($action) && !isset($_POST['update']) && !isset($_POST['test_connection'])) ? false : true;
-		$action = (empty($action)) ? $request->variable('action', '') : $action;
+		$submit = (empty($action) && !$this->request->is_set_post('update') && !$this->request->is_set_post('test_connection')) ? false : true;
+		$action = (empty($action)) ? $this->request->variable('action', '') : $action;
 
 		$form_name = 'acp_lang';
 		add_form_key('acp_lang');
 
-		$lang_id = $request->variable('id', 0);
+		$lang_id = $this->request->variable('id', 0);
 
-		$selected_lang_file = $request->variable('language_file', '|common.' . $phpEx);
+		$selected_lang_file = $this->request->variable('language_file', '|common.' . $this->php_ext);
 
 		list($this->language_directory, $this->language_file) = explode('|', $selected_lang_file);
 
 		$this->language_directory = basename($this->language_directory);
 		$this->language_file = basename($this->language_file);
 
-		$user->add_lang('acp/language');
-		$this->tpl_name = 'acp_language';
-		$this->page_title = 'ACP_LANGUAGE_PACKS';
+		$this->language->add_lang('acp/language');
 
 		switch ($action)
 		{
@@ -68,41 +137,41 @@ class acp_language
 
 				if (!$submit || !check_form_key($form_name))
 				{
-					trigger_error($user->lang['FORM_INVALID']. adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('FORM_INVALID'). adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				if (!$lang_id)
 				{
-					trigger_error($user->lang['NO_LANG_ID'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('NO_LANG_ID') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				$sql = 'SELECT *
 					FROM ' . LANG_TABLE . "
 					WHERE lang_id = $lang_id";
-				$result = $db->sql_query($sql);
-				$row = $db->sql_fetchrow($result);
-				$db->sql_freeresult($result);
+				$result = $this->db->sql_query($sql);
+				$row = $this->db->sql_fetchrow($result);
+				$this->db->sql_freeresult($result);
 
 				$sql_ary	= array(
-					'lang_english_name'		=> $request->variable('lang_english_name', $row['lang_english_name']),
-					'lang_local_name'		=> $request->variable('lang_local_name', $row['lang_local_name'], true),
-					'lang_author'			=> $request->variable('lang_author', $row['lang_author'], true),
+					'lang_english_name'		=> $this->request->variable('lang_english_name', $row['lang_english_name']),
+					'lang_local_name'		=> $this->request->variable('lang_local_name', $row['lang_local_name'], true),
+					'lang_author'			=> $this->request->variable('lang_author', $row['lang_author'], true),
 				);
 
-				$db->sql_query('UPDATE ' . LANG_TABLE . '
-					SET ' . $db->sql_build_array('UPDATE', $sql_ary) . '
+				$this->db->sql_query('UPDATE ' . LANG_TABLE . '
+					SET ' . $this->db->sql_build_array('UPDATE', $sql_ary) . '
 					WHERE lang_id = ' . $lang_id);
 
-				$phpbb_log->add('admin', $user->data['user_id'], $user->ip, 'LOG_LANGUAGE_PACK_UPDATED', false, array($sql_ary['lang_english_name']));
+				$this->log->add('admin', $this->user->data['user_id'], $this->user->ip, 'LOG_LANGUAGE_PACK_UPDATED', false, array($sql_ary['lang_english_name']));
 
-				trigger_error($user->lang['LANGUAGE_DETAILS_UPDATED'] . adm_back_link($this->u_action));
+				trigger_error($this->language->lang('LANGUAGE_DETAILS_UPDATED') . adm_back_link($this->u_action));
 			break;
 
 			case 'details':
 
 				if (!$lang_id)
 				{
-					trigger_error($user->lang['NO_LANG_ID'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('NO_LANG_ID') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				$this->page_title = 'LANGUAGE_PACK_DETAILS';
@@ -110,30 +179,29 @@ class acp_language
 				$sql = 'SELECT *
 					FROM ' . LANG_TABLE . '
 					WHERE lang_id = ' . $lang_id;
-				$result = $db->sql_query($sql);
-				$lang_entries = $db->sql_fetchrow($result);
-				$db->sql_freeresult($result);
+				$result = $this->db->sql_query($sql);
+				$lang_entries = $this->db->sql_fetchrow($result);
+				$this->db->sql_freeresult($result);
 
 				if (!$lang_entries)
 				{
-					trigger_error($user->lang['LANGUAGE_PACK_NOT_EXIST'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('LANGUAGE_PACK_NOT_EXIST') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				$lang_iso = $lang_entries['lang_iso'];
 
-				/** @var \phpbb\language\language_file_helper $language_helper */
-				$language_helper = $phpbb_container->get('language.helper.language_file');
-
 				try
 				{
-					$lang_cfg = $language_helper->get_language_data_from_composer_file("{$phpbb_root_path}language/$lang_iso/composer.json");
+					$lang_cfg = $this->language_helper->get_language_data_from_composer_file("{$this->phpbb_root_path}language/$lang_iso/composer.json");
 				}
 				catch (\DomainException $e)
 				{
-					trigger_error($user->lang['LANGUAGE_PACK_NOT_EXIST'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('LANGUAGE_PACK_NOT_EXIST') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
-				$template->assign_vars(array(
+				$this->language->add_lang('acp/extensions');
+
+				$this->template->assign_vars(array(
 					'S_DETAILS'					=> true,
 					'U_ACTION'					=> $this->u_action . "&action=details&id=$lang_id",
 					'U_BACK'					=> $this->u_action,
@@ -144,19 +212,19 @@ class acp_language
 					'LANG_VERSION'				=> $lang_cfg['version'],
 					'LANG_PHPBB_VERSION'		=> $lang_cfg['phpbb_version'],
 					'LANG_AUTHOR'				=> $lang_entries['lang_author'],
-					'L_MISSING_FILES'			=> $user->lang('THOSE_MISSING_LANG_FILES', $lang_entries['lang_local_name']),
-					'L_MISSING_VARS_EXPLAIN'	=> $user->lang('THOSE_MISSING_LANG_VARIABLES', $lang_entries['lang_local_name']),
+					'L_MISSING_FILES'			=> $this->language->lang('THOSE_MISSING_LANG_FILES', $lang_entries['lang_local_name']),
+					'L_MISSING_VARS_EXPLAIN'	=> $this->language->lang('THOSE_MISSING_LANG_VARIABLES', $lang_entries['lang_local_name']),
 				));
 
 				// If current lang is different from the default lang, then highlight missing files and variables
-				if ($lang_iso != $config['default_lang'])
+				if ($lang_iso != $this->config['default_lang'])
 				{
 					try
 					{
 						$iterator = new \RecursiveIteratorIterator(
 							new \phpbb\recursive_dot_prefix_filter_iterator(
 								new \RecursiveDirectoryIterator(
-									$phpbb_root_path . 'language/' . $config['default_lang'] . '/',
+									$this->phpbb_root_path . 'language/' . $this->config['default_lang'] . '/',
 									\FilesystemIterator::SKIP_DOTS
 								)
 							),
@@ -174,21 +242,21 @@ class acp_language
 						$relative_path = $iterator->getInnerIterator()->getSubPathname();
 						$relative_path = str_replace(DIRECTORY_SEPARATOR, '/', $relative_path);
 
-						if (file_exists($phpbb_root_path . 'language/' . $lang_iso . '/' . $relative_path))
+						if (file_exists($this->phpbb_root_path . 'language/' . $lang_iso . '/' . $relative_path))
 						{
-							if (substr($relative_path, 0 - strlen($phpEx)) === $phpEx)
+							if (substr($relative_path, 0 - strlen($this->php_ext)) === $this->php_ext)
 							{
-								$missing_vars = $this->compare_language_files($config['default_lang'], $lang_iso, $relative_path);
+								$missing_vars = $this->compare_language_files($this->config['default_lang'], $lang_iso, $relative_path);
 
 								if (!empty($missing_vars))
 								{
-									$template->assign_block_vars('missing_varfile', array(
+									$this->template->assign_block_vars('missing_varfile', array(
 										'FILE_NAME'			=> $relative_path,
 									));
 
 									foreach ($missing_vars as $var)
 									{
-										$template->assign_block_vars('missing_varfile.variable', array(
+										$this->template->assign_block_vars('missing_varfile.variable', array(
 												'VAR_NAME'			=> $var,
 										));
 									}
@@ -197,7 +265,7 @@ class acp_language
 						}
 						else
 						{
-							$template->assign_block_vars('missing_files', array(
+							$this->template->assign_block_vars('missing_files', array(
 								'FILE_NAME' => $relative_path,
 							));
 						}
@@ -210,40 +278,40 @@ class acp_language
 
 				if (!$lang_id)
 				{
-					trigger_error($user->lang['NO_LANG_ID'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('NO_LANG_ID') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				$sql = 'SELECT *
 					FROM ' . LANG_TABLE . '
 					WHERE lang_id = ' . $lang_id;
-				$result = $db->sql_query($sql);
-				$row = $db->sql_fetchrow($result);
-				$db->sql_freeresult($result);
+				$result = $this->db->sql_query($sql);
+				$row = $this->db->sql_fetchrow($result);
+				$this->db->sql_freeresult($result);
 
-				if ($row['lang_iso'] == $config['default_lang'])
+				if ($row['lang_iso'] == $this->config['default_lang'])
 				{
-					trigger_error($user->lang['NO_REMOVE_DEFAULT_LANG'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('NO_REMOVE_DEFAULT_LANG') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				if (confirm_box(true))
 				{
-					$db->sql_query('DELETE FROM ' . LANG_TABLE . ' WHERE lang_id = ' . $lang_id);
+					$this->db->sql_query('DELETE FROM ' . LANG_TABLE . ' WHERE lang_id = ' . $lang_id);
 
 					$sql = 'UPDATE ' . USERS_TABLE . "
-						SET user_lang = '" . $db->sql_escape($config['default_lang']) . "'
-						WHERE user_lang = '" . $db->sql_escape($row['lang_iso']) . "'";
-					$db->sql_query($sql);
+						SET user_lang = '" . $this->db->sql_escape($this->config['default_lang']) . "'
+						WHERE user_lang = '" . $this->db->sql_escape($row['lang_iso']) . "'";
+					$this->db->sql_query($sql);
 
 					// We also need to remove the translated entries for custom profile fields - we want clean tables, don't we?
 					$sql = 'DELETE FROM ' . PROFILE_LANG_TABLE . ' WHERE lang_id = ' . $lang_id;
-					$db->sql_query($sql);
+					$this->db->sql_query($sql);
 
 					$sql = 'DELETE FROM ' . PROFILE_FIELDS_LANG_TABLE . ' WHERE lang_id = ' . $lang_id;
-					$db->sql_query($sql);
+					$this->db->sql_query($sql);
 
-					$phpbb_log->add('admin', $user->data['user_id'], $user->ip, 'LOG_LANGUAGE_PACK_DELETED', false, array($row['lang_english_name']));
+					$this->log->add('admin', $this->user->data['user_id'], $this->user->ip, 'LOG_LANGUAGE_PACK_DELETED', false, array($row['lang_english_name']));
 
-					$delete_message = sprintf($user->lang['LANGUAGE_PACK_DELETED'], $row['lang_english_name']);
+					$delete_message = $this->language->lang('LANGUAGE_PACK_DELETED', $row['lang_english_name']);
 					$lang_iso = $row['lang_iso'];
 					/**
 					 * Run code after language deleted
@@ -254,7 +322,7 @@ class acp_language
 					 * @since 3.2.2-RC1
 					 */
 					$vars = array('lang_iso', 'delete_message');
-					extract($phpbb_dispatcher->trigger_event('core.acp_language_after_delete', compact($vars)));
+					extract($this->dispatcher->trigger_event('core.acp_language_after_delete', compact($vars)));
 
 					trigger_error($delete_message . adm_back_link($this->u_action));
 				}
@@ -266,50 +334,48 @@ class acp_language
 						'action'	=> $action,
 						'id'		=> $lang_id,
 					);
-					confirm_box(false, $user->lang('DELETE_LANGUAGE_CONFIRM', $row['lang_english_name']), build_hidden_fields($s_hidden_fields));
+					confirm_box(false, $this->language->lang('DELETE_LANGUAGE_CONFIRM', $row['lang_english_name']), build_hidden_fields($s_hidden_fields));
 				}
 			break;
 
 			case 'install':
-				if (!check_link_hash($request->variable('hash', ''), 'acp_language'))
+				if (!check_link_hash($this->request->variable('hash', ''), 'acp_language'))
 				{
-					trigger_error($user->lang['FORM_INVALID'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('FORM_INVALID') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
-				$lang_iso = $request->variable('iso', '');
+				$lang_iso = $this->request->variable('iso', '');
 				$lang_iso = basename($lang_iso);
 
-				if (!$lang_iso || !file_exists("{$phpbb_root_path}language/$lang_iso/composer.json"))
+				if (!$lang_iso || !file_exists("{$this->phpbb_root_path}language/$lang_iso/composer.json"))
 				{
-					trigger_error($user->lang['LANGUAGE_PACK_NOT_EXIST'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('LANGUAGE_PACK_NOT_EXIST') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
-				/** @var \phpbb\language\language_file_helper $language_helper */
-				$language_helper = $phpbb_container->get('language.helper.language_file');
 				try
 				{
-					$lang_pack = $language_helper->get_language_data_from_composer_file("{$phpbb_root_path}language/$lang_iso/composer.json");
+					$lang_pack = $this->language_helper->get_language_data_from_composer_file("{$this->phpbb_root_path}language/$lang_iso/composer.json");
 				}
 				catch (\DomainException $e)
 				{
-					trigger_error($user->lang['LANGUAGE_PACK_NOT_EXIST'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('LANGUAGE_PACK_NOT_EXIST') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				$sql = 'SELECT lang_iso
 					FROM ' . LANG_TABLE . "
-					WHERE lang_iso = '" . $db->sql_escape($lang_iso) . "'";
-				$result = $db->sql_query($sql);
-				$row = $db->sql_fetchrow($result);
-				$db->sql_freeresult($result);
+					WHERE lang_iso = '" . $this->db->sql_escape($lang_iso) . "'";
+				$result = $this->db->sql_query($sql);
+				$row = $this->db->sql_fetchrow($result);
+				$this->db->sql_freeresult($result);
 
 				if ($row)
 				{
-					trigger_error($user->lang['LANGUAGE_PACK_ALREADY_INSTALLED'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('LANGUAGE_PACK_ALREADY_INSTALLED') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				if (!$lang_pack['name'] || !$lang_pack['local_name'])
 				{
-					trigger_error($user->lang['INVALID_LANGUAGE_PACK'] . adm_back_link($this->u_action), E_USER_WARNING);
+					trigger_error($this->language->lang('INVALID_LANGUAGE_PACK') . adm_back_link($this->u_action), E_USER_WARNING);
 				}
 
 				// Add language pack
@@ -321,16 +387,16 @@ class acp_language
 					'lang_author'		=> $lang_pack['author']
 				);
 
-				$db->sql_query('INSERT INTO ' . LANG_TABLE . ' ' . $db->sql_build_array('INSERT', $sql_ary));
-				$lang_id = $db->sql_nextid();
+				$this->db->sql_query('INSERT INTO ' . LANG_TABLE . ' ' . $this->db->sql_build_array('INSERT', $sql_ary));
+				$lang_id = $this->db->sql_nextid();
 
 				// Now let's copy the default language entries for custom profile fields for this new language - makes admin's life easier.
 				$sql = 'SELECT lang_id
 					FROM ' . LANG_TABLE . "
-					WHERE lang_iso = '" . $db->sql_escape($config['default_lang']) . "'";
-				$result = $db->sql_query($sql);
-				$default_lang_id = (int) $db->sql_fetchfield('lang_id');
-				$db->sql_freeresult($result);
+					WHERE lang_iso = '" . $this->db->sql_escape($this->config['default_lang']) . "'";
+				$result = $this->db->sql_query($sql);
+				$default_lang_id = (int) $this->db->sql_fetchfield('lang_id');
+				$this->db->sql_freeresult($result);
 
 				// We want to notify the admin that custom profile fields need to be updated for the new language.
 				$notify_cpf_update = false;
@@ -342,33 +408,33 @@ class acp_language
 				$sql = 'SELECT field_id, lang_name, lang_explain, lang_default_value
 					FROM ' . PROFILE_LANG_TABLE . '
 					WHERE lang_id = ' . $default_lang_id;
-				$result = $db->sql_query($sql);
+				$result = $this->db->sql_query($sql);
 
-				while ($row = $db->sql_fetchrow($result))
+				while ($row = $this->db->sql_fetchrow($result))
 				{
 					$row['lang_id'] = $lang_id;
-					$db->sql_query('INSERT INTO ' . PROFILE_LANG_TABLE . ' ' . $db->sql_build_array('INSERT', $row));
+					$this->db->sql_query('INSERT INTO ' . PROFILE_LANG_TABLE . ' ' . $this->db->sql_build_array('INSERT', $row));
 					$notify_cpf_update = true;
 				}
-				$db->sql_freeresult($result);
+				$this->db->sql_freeresult($result);
 
 				$sql = 'SELECT field_id, option_id, field_type, lang_value
 					FROM ' . PROFILE_FIELDS_LANG_TABLE . '
 					WHERE lang_id = ' . $default_lang_id;
-				$result = $db->sql_query($sql);
+				$result = $this->db->sql_query($sql);
 
-				while ($row = $db->sql_fetchrow($result))
+				while ($row = $this->db->sql_fetchrow($result))
 				{
 					$row['lang_id'] = $lang_id;
-					$db->sql_query('INSERT INTO ' . PROFILE_FIELDS_LANG_TABLE . ' ' . $db->sql_build_array('INSERT', $row));
+					$this->db->sql_query('INSERT INTO ' . PROFILE_FIELDS_LANG_TABLE . ' ' . $this->db->sql_build_array('INSERT', $row));
 					$notify_cpf_update = true;
 				}
-				$db->sql_freeresult($result);
+				$this->db->sql_freeresult($result);
 
-				$phpbb_log->add('admin', $user->data['user_id'], $user->ip, 'LOG_LANGUAGE_PACK_INSTALLED', false, array($lang_pack['name']));
+				$this->log->add('admin', $this->user->data['user_id'], $this->user->ip, 'LOG_LANGUAGE_PACK_INSTALLED', false, array($lang_pack['name']));
 
-				$message = sprintf($user->lang['LANGUAGE_PACK_INSTALLED'], $lang_pack['name']);
-				$message .= ($notify_cpf_update) ? '<br /><br />' . $user->lang['LANGUAGE_PACK_CPF_UPDATE'] : '';
+				$message = $this->language->lang('LANGUAGE_PACK_INSTALLED', $lang_pack['name']);
+				$message .= ($notify_cpf_update) ? '<br /><br />' . $this->language->lang('LANGUAGE_PACK_CPF_UPDATE') : '';
 				trigger_error($message . adm_back_link($this->u_action));
 
 			break;
@@ -377,28 +443,28 @@ class acp_language
 		$sql = 'SELECT user_lang, COUNT(user_lang) AS lang_count
 			FROM ' . USERS_TABLE . '
 			GROUP BY user_lang';
-		$result = $db->sql_query($sql);
+		$result = $this->db->sql_query($sql);
 
 		$lang_count = array();
-		while ($row = $db->sql_fetchrow($result))
+		while ($row = $this->db->sql_fetchrow($result))
 		{
 			$lang_count[$row['user_lang']] = $row['lang_count'];
 		}
-		$db->sql_freeresult($result);
+		$this->db->sql_freeresult($result);
 
 		$sql = 'SELECT *
 			FROM ' . LANG_TABLE . '
 			ORDER BY lang_english_name';
-		$result = $db->sql_query($sql);
+		$result = $this->db->sql_query($sql);
 
 		$installed = array();
 
-		while ($row = $db->sql_fetchrow($result))
+		while ($row = $this->db->sql_fetchrow($result))
 		{
 			$installed[] = $row['lang_iso'];
-			$tagstyle = ($row['lang_iso'] == $config['default_lang']) ? '*' : '';
+			$tagstyle = ($row['lang_iso'] == $this->config['default_lang']) ? '*' : '';
 
-			$template->assign_block_vars('lang', array(
+			$this->template->assign_block_vars('lang', array(
 				'U_DETAILS'			=> $this->u_action . "&amp;action=details&amp;id={$row['lang_id']}",
 				'U_DOWNLOAD'		=> $this->u_action . "&amp;action=download&amp;id={$row['lang_id']}",
 				'U_DELETE'			=> $this->u_action . "&amp;action=delete&amp;id={$row['lang_id']}",
@@ -410,13 +476,11 @@ class acp_language
 				'USED_BY'			=> (isset($lang_count[$row['lang_iso']])) ? $lang_count[$row['lang_iso']] : 0,
 			));
 		}
-		$db->sql_freeresult($result);
+		$this->db->sql_freeresult($result);
 
 		$new_ary = $iso = array();
 
-		/** @var \phpbb\language\language_file_helper $language_helper */
-		$language_helper = $phpbb_container->get('language.helper.language_file');
-		$iso = $language_helper->get_available_languages();
+		$iso = $this->language_helper->get_available_languages();
 
 		foreach ($iso as $lang_array)
 		{
@@ -434,7 +498,7 @@ class acp_language
 		{
 			foreach ($new_ary as $iso => $lang_ary)
 			{
-				$template->assign_block_vars('notinst', array(
+				$this->template->assign_block_vars('notinst', array(
 					'ISO'			=> htmlspecialchars($lang_ary['iso'], ENT_COMPAT),
 					'LOCAL_NAME'	=> htmlspecialchars($lang_ary['local_name'], ENT_COMPAT, 'UTF-8'),
 					'NAME'			=> htmlspecialchars($lang_ary['name'], ENT_COMPAT, 'UTF-8'),
@@ -451,10 +515,8 @@ class acp_language
 	*/
 	function compare_language_files($source_lang, $dest_lang, $file)
 	{
-		global $phpbb_root_path;
-
-		$source_file = $phpbb_root_path . 'language/' . $source_lang . '/' . $file;
-		$dest_file = $phpbb_root_path . 'language/' . $dest_lang . '/' . $file;
+		$source_file = $this->phpbb_root_path . 'language/' . $source_lang . '/' . $file;
+		$dest_file = $this->phpbb_root_path . 'language/' . $dest_lang . '/' . $file;
 
 		if (!file_exists($dest_file))
 		{