diff --git a/phpBB/adm/style/acp_ext_gallery.html b/phpBB/adm/style/acp_ext_gallery.html
index b2ef033288..dfd8ffaf04 100644
--- a/phpBB/adm/style/acp_ext_gallery.html
+++ b/phpBB/adm/style/acp_ext_gallery.html
@@ -2,9 +2,9 @@
 
 <a id="maincontent"></a>
 
-<h1>{{lang( 'EXTENSIONS_ADMIN') }}</h1>
+<h1>{{lang( 'EXTENSIONS_GALLERY') }}</h1>
 
-<p>{{lang( 'EXTENSIONS_EXPLAIN') }}</p>
+<p>{{lang( 'EXTENSIONS_GALLERY_EXPLAIN') }}</p>
 
 <fieldset class="quick quick-left">
 	<span class="small"><a href="https://www.phpbb.com/go/customise/extensions/3.1" target="_blank">{{ lang('BROWSE_EXTENSIONS_DATABASE') }}</a> &bull; <a href="javascript:phpbb.toggleDisplay('gallery_settings');">{{ lang('SETTINGS') }}</a></span>
diff --git a/phpBB/includes/acp/acp_extensions.php b/phpBB/includes/acp/acp_extensions.php
index eec896cbfe..28f102e006 100644
--- a/phpBB/includes/acp/acp_extensions.php
+++ b/phpBB/includes/acp/acp_extensions.php
@@ -566,7 +566,7 @@ class acp_extensions
 
 				$this->template->assign_vars(array(
 						'MESSAGE_TITLE'			=> $language->lang('ACP_EXTENSIONS_MANAGE'),
-						'MESSAGE_TEXT'			=> $language->lang('EXTENSION_MANAGED') . adm_back_link($this->u_action),
+						'MESSAGE_TEXT'			=> $language->lang('EXTENSION_MANAGED_SUCCESS', $extension) . adm_back_link($this->u_action),
 						'MESSAGE_DETAIL'		=> $composer_io->getOutput(),
 						'MESSAGE_DETAIL_LEGEND'	=> $language->lang('COMPOSER_OUTPUT'),
 						'S_USER_NOTICE'			=> true,
@@ -642,6 +642,7 @@ class acp_extensions
 					'purge_on_remove' => $this->config['exts_composer_purge_on_remove'],
 					'repositories' => unserialize($this->config['exts_composer_repositories']),
 				]);
+				$this->template->assign_var('enabled', $this->manager->check_requirements());
 				$this->request->disable_super_globals();
 
 				add_form_key('gallery_settings');
diff --git a/phpBB/language/en/acp/common.php b/phpBB/language/en/acp/common.php
index 40b4a5d9d4..4657c08bcf 100644
--- a/phpBB/language/en/acp/common.php
+++ b/phpBB/language/en/acp/common.php
@@ -89,6 +89,10 @@ $lang = array_merge($lang, array(
 	'ACP_EXTENSION_MANAGEMENT'	=> 'Extension management',
 	'ACP_EXTENSIONS'			=> 'Manage extensions',
 	'ACP_EXTENSIONS_GALLERY'	=> 'Extensions gallery',
+	'ACP_EXTENSIONS_INSTALL'	=> 'Install extensions',
+	'ACP_EXTENSIONS_REMOVE'		=> 'Remove extensions',
+	'ACP_EXTENSIONS_UPDATE'		=> 'Update extensions',
+	'ACP_EXTENSIONS_MANAGE'		=> 'Manage extension automatically',
 
 	'ACP_FORUM_BASED_PERMISSIONS'	=> 'Forum based permissions',
 	'ACP_FORUM_LOGS'				=> 'Forum logs',
@@ -250,6 +254,7 @@ $lang = array_merge($lang, array(
 	'COMPOSER_INSTALLING_PACKAGE'		=> '  - Installing %1$s (%2$s)',
 	'COMPOSER_DELETING'					=> '  - Deleting %s',
 	'COMPOSER_UPDATE_NOTHING'			=> 'Nothing to update',
+	'COMPOSER_OUTPUT'					=> 'Composer output',
 
 	'CONFIG_UPDATED'		=> 'Configuration updated successfully.',
 	'CRON_LOCK_ERROR'		=> 'Could not obtain cron lock.',
diff --git a/phpBB/language/en/acp/extensions.php b/phpBB/language/en/acp/extensions.php
index e3ba8e89ea..55a8778be0 100644
--- a/phpBB/language/en/acp/extensions.php
+++ b/phpBB/language/en/acp/extensions.php
@@ -45,6 +45,12 @@ $lang = array_merge($lang, array(
 	'EXTENSION_MANAGED_WITH_ENABLE_ERROR'		=> 'The “%s” extension has been installed but an error occurred when re-enabling it.',
 	'EXTENSION_NOT_INSTALLED'					=> 'The “%s” extension is not installed.',
 
+	'ENABLING_EXTENSIONS'	=> 'Enabling extensions',
+	'DISABLING_EXTENSIONS'	=> 'Disabling extensions',
+
+	'EXTENSIONS_GALLERY' => 'Extensions Gallery',
+	'EXTENSIONS_GALLERY_EXPLAIN' => 'The Extensions Gallery is a tool in your phpBB Board which allows you to see all the extensions that are available for your board.',
+
 	'EXTENSION'					=> 'Extension',
 	'EXTENSIONS'				=> 'Extensions',
 	'EXTENSIONS_ADMIN'			=> 'Extensions Manager',
@@ -148,10 +154,12 @@ $lang = array_merge($lang, array(
 	'ENABLE_ON_INSTALL'				=> 'Enable extensions when installing',
 	'PURGE_ON_REMOVE'				=> 'Purge extensions when removing',
 	'ENABLE_PACKAGIST'				=> 'Enable Packagist usage',
-	'ENABLE_PACKAGIST_EXPLAIN'		=> 'TODO text explaining why packagist shouldn\'t be enabled, dev usage, etc...',
+	'ENABLE_PACKAGIST_EXPLAIN'		=> 'TODO: text explaining why packagist shouldn\'t be enabled, dev usage, etc...',
+	'ENABLE_PACKAGIST_CONFIRM'		=> 'TODO: are you sure you ant to enable packagist?',
 
-	'EXTENSION_MANAGED_SUCCESS'	=> 'The extension %s is now managed automatically.',
-	'EXTENSIONS_INSTALLED'		=> 'Extensions successfully installed.',
-	'EXTENSIONS_REMOVED'		=> 'Extensions successfully removed.',
-	'EXTENSIONS_UPDATED'		=> 'Extensions successfully updated..',
+	'EXTENSION_MANAGED_SUCCESS'		=> 'The extension %s is now managed automatically.',
+	'EXTENSIONS_INSTALLED'			=> 'Extensions successfully installed.',
+	'EXTENSIONS_REMOVED'			=> 'Extensions successfully removed.',
+	'EXTENSIONS_UPDATED'			=> 'Extensions successfully updated.',
+	'EXTENSIONS_DIR_NOT_WRITABLE'	=> 'The extension directory is not writable',
 ));
diff --git a/phpBB/phpbb/composer/manager.php b/phpBB/phpbb/composer/manager.php
index 1941e79fff..286551ae95 100644
--- a/phpBB/phpbb/composer/manager.php
+++ b/phpBB/phpbb/composer/manager.php
@@ -271,6 +271,14 @@ class manager implements manager_interface
 		throw new \phpbb\exception\runtime_exception('COMPOSER_UNSUPPORTED_OPERATION', (array) $this->package_type);
 	}
 
+	/**
+	 * {@inheritdoc}
+	 */
+	public function check_requirements()
+	{
+		return true;
+	}
+
 	protected function normalize_version($packages)
 	{
 		$normalized_packages = [];
diff --git a/phpBB/phpbb/composer/manager_interface.php b/phpBB/phpbb/composer/manager_interface.php
index 2572ba0831..ab36f58dc9 100644
--- a/phpBB/phpbb/composer/manager_interface.php
+++ b/phpBB/phpbb/composer/manager_interface.php
@@ -89,4 +89,11 @@ interface manager_interface
 	 * @throws runtime_exception
 	 */
 	public function start_managing($package, $io);
+
+	/**
+	 * Checks the requirements of the manager and returns true if it can be used.
+	 *
+	 * @return bool
+	 */
+	public function check_requirements();
 }