diff --git a/phpBB/includes/constants.php b/phpBB/includes/constants.php
index 0ef409767d..825a328d39 100644
--- a/phpBB/includes/constants.php
+++ b/phpBB/includes/constants.php
@@ -152,13 +152,13 @@ define('FULL_FOLDER_DELETE', -2);
 define('FULL_FOLDER_HOLD', -1);
 
 // Confirm types
-/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\plugin_interface::CONFIRM_REGISTRATION, to be removed in 5.0.0-a1 */
+/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\confirm_type::REGISTRATION, to be removed in 5.0.0-a1 */
 define('CONFIRM_REG', 1);
-/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\plugin_interface::CONFIRM_LOGIN, to be removed in 5.0.0-a1 */
+/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\confirm_type::LOGIN, to be removed in 5.0.0-a1 */
 define('CONFIRM_LOGIN', 2);
-/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\plugin_interface::CONFIRM_POST, to be removed in 5.0.0-a1 */
+/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\confirm_type::POST, to be removed in 5.0.0-a1 */
 define('CONFIRM_POST', 3);
-/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\plugin_interface::CONFIRM_REPORT, to be removed in 5.0.0-a1 */
+/** @deprecated 4.0.0-a1 Replaced by \phpbb\captcha\plugins\confirm_type::REPORT, to be removed in 5.0.0-a1 */
 define('CONFIRM_REPORT', 4);
 
 // Categories - Attachments
diff --git a/phpBB/includes/ucp/ucp_register.php b/phpBB/includes/ucp/ucp_register.php
index ad2ad79dbe..b8d0d78b40 100644
--- a/phpBB/includes/ucp/ucp_register.php
+++ b/phpBB/includes/ucp/ucp_register.php
@@ -238,7 +238,7 @@ class ucp_register
 			/** @var \phpbb\captcha\factory $captcha_factory */
 			$captcha_factory = $phpbb_container->get('captcha.factory');
 			$captcha = $captcha_factory->get_instance($config['captcha_plugin']);
-			$captcha->init(\phpbb\captcha\plugins\plugin_interface::CONFIRM_REGISTRATION);
+			$captcha->init(\phpbb\captcha\plugins\confirm_type::REGISTRATION);
 		}
 
 		$timezone = $config['board_timezone'];
diff --git a/phpBB/phpbb/auth/provider/db.php b/phpBB/phpbb/auth/provider/db.php
index 6911adfaff..5f8ebd6ac3 100644
--- a/phpBB/phpbb/auth/provider/db.php
+++ b/phpBB/phpbb/auth/provider/db.php
@@ -176,7 +176,7 @@ class db extends base
 		// Every auth module is able to define what to do by itself...
 		if ($show_captcha)
 		{
-			$captcha->init(\phpbb\captcha\plugins\plugin_interface::CONFIRM_LOGIN);
+			$captcha->init(\phpbb\captcha\plugins\confirm_type::LOGIN);
 			if ($captcha->validate() !== true)
 			{
 				return array(
diff --git a/phpBB/phpbb/captcha/plugins/confirm_type.php b/phpBB/phpbb/captcha/plugins/confirm_type.php
new file mode 100644
index 0000000000..db8bb54bd2
--- /dev/null
+++ b/phpBB/phpbb/captcha/plugins/confirm_type.php
@@ -0,0 +1,24 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\captcha\plugins;
+
+/**
+ * Confirmation types for CAPTCHA plugins
+ */
+enum confirm_type: int {
+	case REGISTRATION = 1;
+	case LOGIN = 2;
+	case POST = 3;
+	case REPORT = 4;
+}
diff --git a/phpBB/phpbb/captcha/plugins/plugin_interface.php b/phpBB/phpbb/captcha/plugins/plugin_interface.php
index bc20b2e703..c6e4e6c6de 100644
--- a/phpBB/phpbb/captcha/plugins/plugin_interface.php
+++ b/phpBB/phpbb/captcha/plugins/plugin_interface.php
@@ -15,14 +15,6 @@ namespace phpbb\captcha\plugins;
 
 interface plugin_interface
 {
-	const CONFIRM_REGISTRATION = 1;
-	const CONFIRM_LOGIN = 2;
-
-	const CONFIRM_POST = 3;
-
-	const CONFIRM_REPORT = 4;
-
-
 	/**
 	 * Check if the plugin is available
 	 *
@@ -54,10 +46,10 @@ interface plugin_interface
 	/**
 	 * Display the captcha for the specified type
 	 *
-	 * @param int $type Type of captcha, should be one of the CONFIRMATION_* constants
+	 * @param confirm_type $type Type of captcha, should be one of the CONFIRMATION_* constants
 	 * @return void
 	 */
-	public function init(int $type): void;
+	public function init(confirm_type $type): void;
 
 	/**
 	 * Get hidden form fields for this captcha plugin
diff --git a/phpBB/phpbb/captcha/plugins/turnstile.php b/phpBB/phpbb/captcha/plugins/turnstile.php
index b3152b2a23..f5bd22602b 100644
--- a/phpBB/phpbb/captcha/plugins/turnstile.php
+++ b/phpBB/phpbb/captcha/plugins/turnstile.php
@@ -121,7 +121,7 @@ class turnstile extends base
 	/**
 	 * {@inheritDoc}
 	 */
-	public function init(int $type): void
+	public function init(confirm_type $type): void
 	{
 		$this->language->add_lang('captcha_turnstile');
 	}
diff --git a/phpBB/phpbb/report/controller/report.php b/phpBB/phpbb/report/controller/report.php
index 7d41c1c47f..97dbdbd9bb 100644
--- a/phpBB/phpbb/report/controller/report.php
+++ b/phpBB/phpbb/report/controller/report.php
@@ -13,6 +13,7 @@
 
 namespace phpbb\report\controller;
 
+use phpbb\captcha\plugins\confirm_type;
 use phpbb\captcha\plugins\plugin_interface;
 use phpbb\exception\http_exception;
 use phpbb\report\report_handler_interface;
@@ -132,7 +133,7 @@ class report
 		if ($this->config['enable_post_confirm'] && !$this->user->data['is_registered'])
 		{
 			$captcha = $this->captcha_factory->get_instance($this->config['captcha_plugin']);
-			$captcha->init(plugin_interface::CONFIRM_REPORT);
+			$captcha->init(confirm_type::REPORT);
 		}
 
 		//Has the report been cancelled?
diff --git a/phpBB/posting.php b/phpBB/posting.php
index fb54f05ff6..9f8cce0ead 100644
--- a/phpBB/posting.php
+++ b/phpBB/posting.php
@@ -458,7 +458,7 @@ if ($config['enable_post_confirm'] && !$user->data['is_registered'])
 	/** @var \phpbb\captcha\factory $captcha_factory */
 	$captcha_factory = $phpbb_container->get('captcha.factory');
 	$captcha = $captcha_factory->get_instance($config['captcha_plugin']);
-	$captcha->init(\phpbb\captcha\plugins\plugin_interface::CONFIRM_POST);
+	$captcha->init(\phpbb\captcha\plugins\confirm_type::POST);
 }
 
 // Is the user able to post within this forum?