diff --git a/phpBB/includes/acp/acp_captcha.php b/phpBB/includes/acp/acp_captcha.php
index ff9f515d32..69e13463ab 100644
--- a/phpBB/includes/acp/acp_captcha.php
+++ b/phpBB/includes/acp/acp_captcha.php
@@ -128,11 +128,9 @@ class acp_captcha
 					if (isset($captchas['available'][$selected]))
 					{
 						$old_captcha = $factory->get_instance($config['captcha_plugin']);
-						$old_captcha->uninstall();
+						$old_captcha->garbage_collect();
 
 						$config->set('captcha_plugin', $selected);
-						$new_captcha = $factory->get_instance($config['captcha_plugin']);
-						$new_captcha->install();
 
 						$phpbb_log->add('admin', $user->data['user_id'], $user->ip, 'LOG_CONFIG_VISUAL');
 					}
diff --git a/phpBB/phpbb/captcha/plugins/captcha_abstract.php b/phpBB/phpbb/captcha/plugins/captcha_abstract.php
index 012e28c987..fb8ccc5a70 100644
--- a/phpBB/phpbb/captcha/plugins/captcha_abstract.php
+++ b/phpBB/phpbb/captcha/plugins/captcha_abstract.php
@@ -184,11 +184,6 @@ abstract class captcha_abstract
 		$this->garbage_collect(0);
 	}
 
-	function install()
-	{
-		return;
-	}
-
 	function validate()
 	{
 		global $user;
diff --git a/phpBB/phpbb/captcha/plugins/legacy_wrapper.php b/phpBB/phpbb/captcha/plugins/legacy_wrapper.php
index bceb771800..e57abbb967 100644
--- a/phpBB/phpbb/captcha/plugins/legacy_wrapper.php
+++ b/phpBB/phpbb/captcha/plugins/legacy_wrapper.php
@@ -25,8 +25,7 @@ class legacy_wrapper implements plugin_interface
 	}
 
 	/**
-	 * Check if the plugin is available
-	 * @return bool True if the plugin is available, false if not
+	 * {@inheritDoc}
 	 */
 	public function is_available(): bool
 	{
@@ -39,9 +38,7 @@ class legacy_wrapper implements plugin_interface
 	}
 
 	/**
-	 * Check if the plugin has a configuration
-	 *
-	 * @return bool True if the plugin has a configuration, false if not
+	 * {@inheritDoc}
 	 */
 	public function has_config(): bool
 	{
@@ -54,9 +51,7 @@ class legacy_wrapper implements plugin_interface
 	}
 
 	/**
-	 * Get the name of the plugin, should be language variable
-	 *
-	 * @return string
+	 * {@inheritDoc}
 	 */
 	public function get_name(): string
 	{
@@ -69,10 +64,7 @@ class legacy_wrapper implements plugin_interface
 	}
 
 	/**
-	 * Display the captcha for the specified type
-	 *
-	 * @param int $type Type of captcha, should be one of the CONFIRMATION_* constants
-	 * @return void
+	 * {@inheritDoc}
 	 */
 	public function init(int $type): void
 	{
@@ -139,4 +131,36 @@ class legacy_wrapper implements plugin_interface
 		// Ensure this is deemed as too many attempts
 		return PHP_INT_MAX;
 	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function get_demo_template(): string
+	{
+		if (method_exists($this->legacy_captcha, 'get_demo_template'))
+		{
+			return $this->legacy_captcha->get_demo_template(0);
+		}
+
+		return '';
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function garbage_collect(int $confirm_type = 0): void
+	{
+		if (method_exists($this->legacy_captcha, 'garbage_collect'))
+		{
+			$this->legacy_captcha->garbage_collect($confirm_type);
+		}
+	}
+
+	public function acp_page($id, $module): void
+	{
+		if (method_exists($this->legacy_captcha, 'acp_page'))
+		{
+			$this->legacy_captcha->acp_page($id, $module);
+		}
+	}
 }
diff --git a/phpBB/phpbb/captcha/plugins/plugin_interface.php b/phpBB/phpbb/captcha/plugins/plugin_interface.php
index 9d0b0cb4de..41e825fad3 100644
--- a/phpBB/phpbb/captcha/plugins/plugin_interface.php
+++ b/phpBB/phpbb/captcha/plugins/plugin_interface.php
@@ -80,4 +80,21 @@ interface plugin_interface
 	 * @return int Number of attempts
 	 */
 	public function get_attempt_count(): int;
+
+	/**
+	 * Get template data for demo
+	 *
+	 * @return string Demo template file name
+	 */
+	public function get_demo_template(): string;
+
+	/**
+	 * Garbage collect captcha plugin
+	 *
+	 * @param int $confirm_type Confirm type to garbage collect, defaults to all (0)
+	 * @return void
+	 */
+	public function garbage_collect(int $confirm_type = 0): void;
+
+	public function acp_page($id, $module): void;
 }
diff --git a/phpBB/phpbb/captcha/plugins/qa.php b/phpBB/phpbb/captcha/plugins/qa.php
index 106cedb7c2..ffc67a7706 100644
--- a/phpBB/phpbb/captcha/plugins/qa.php
+++ b/phpBB/phpbb/captcha/plugins/qa.php
@@ -331,13 +331,6 @@ class qa
 		$this->garbage_collect(0);
 	}
 
-	/**
-	*  API function - set up shop
-	*/
-	function install()
-	{
-	}
-
 	/**
 	*  API function - see what has to be done to validate
 	*/
@@ -597,11 +590,6 @@ class qa
 		$user->add_lang('acp/board');
 		$user->add_lang('captcha_qa');
 
-		if (!self::is_installed())
-		{
-			$this->install();
-		}
-
 		$module->tpl_name = 'captcha_qa_acp';
 		$module->page_title = 'ACP_VC_SETTINGS';
 		$form_key = 'acp_captcha';
diff --git a/phpBB/phpbb/captcha/plugins/recaptcha.php b/phpBB/phpbb/captcha/plugins/recaptcha.php
index ef30baaa9b..a5dcf4efc6 100644
--- a/phpBB/phpbb/captcha/plugins/recaptcha.php
+++ b/phpBB/phpbb/captcha/plugins/recaptcha.php
@@ -184,11 +184,6 @@ class recaptcha extends captcha_abstract
 		$this->garbage_collect(0);
 	}
 
-	function install()
-	{
-		return;
-	}
-
 	function validate()
 	{
 		if (!parent::validate())