diff --git a/README.md b/README.md
index b1e0e6d..1d07044 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,6 @@ This is the repository for the development of the Topic Prefixes phpBB extension
 
 [![Build Status](https://github.com/phpbb-extensions/topicprefixes/actions/workflows/tests.yml/badge.svg)](https://github.com/phpbb-extensions/topicprefixes/actions)
 [![codecov](https://codecov.io/gh/phpbb-extensions/topicprefixes/branch/master/graph/badge.svg?token=Dc0GWOeQWj)](https://codecov.io/gh/phpbb-extensions/topicprefixes)
-[![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/phpbb-extensions/topicprefixes/badges/quality-score.png?b=master)](https://scrutinizer-ci.com/g/phpbb-extensions/topicprefixes/?branch=master)
 
 The phpBB Topic Prefixes extension allows phpBB board administrators to create topic prefix tags that users can easily add to their topic titles. Features include:
 
diff --git a/adm/style/acp_topic_prefixes.css b/adm/style/acp_topic_prefixes.css
new file mode 100644
index 0000000..3c73b32
--- /dev/null
+++ b/adm/style/acp_topic_prefixes.css
@@ -0,0 +1,12 @@
+.tp-toggle-on,
+.tp-toggle-off {
+	font-weight: 900;
+}
+
+.tp-toggle-on:before {
+	content: "\f205";
+}
+
+.tp-toggle-off:before {
+	content: "\f204";
+}
diff --git a/adm/style/acp_topic_prefixes.html b/adm/style/acp_topic_prefixes.html
index 1523b45..9677ca3 100644
--- a/adm/style/acp_topic_prefixes.html
+++ b/adm/style/acp_topic_prefixes.html
@@ -34,7 +34,7 @@ <h1>{{ lang('TOPIC_PREFIXES') }}</h1>
 				<td><strong>{{ prefix.PREFIX_TAG }}</strong></td>
 				<td>
 					<a href="{{ prefix.U_EDIT }}" style="text-decoration: none" title="{{ lang('TOPIC_PREFIX_TOGGLE_STATE') }}" data-ajax="tp_toggle">
-						<i class="icon acp-icon fa-toggle-{{ prefix.PREFIX_ENABLED ? 'on' : 'off' }} fa-fw"></i>
+						<i class="fa fa-fw tp-toggle-{{ prefix.PREFIX_ENABLED ? 'on' : 'off' }} acp-icon"></i>
 					</a>
 				</td>
 				<td class="actions">
@@ -56,10 +56,10 @@ <h1>{{ lang('TOPIC_PREFIXES') }}</h1>
 	<form id="acp_add_topic_prefix" method="post" action="{{ U_ACTION }}">
 		<fieldset class="quick">
 			{{ lang('CREATE_TOPIC_PREFIX') ~ lang('COLON') }}
-			<input type="text" name="prefix_tag" value="" maxlength="200" placeholder="{{ lang('TOPIC_PREFIX_PLACEHOLDER') }}" />
-			<input class="button2" name="submit" type="submit" value="{{ lang('SUBMIT') }}" />
-			<input type="hidden" name="action" value="add" />
-			<input type="hidden" name="forum_id" value="{{ FORUM_ID }}" />
+			<input type="text" name="prefix_tag" value="" maxlength="200" placeholder="{{ lang('TOPIC_PREFIX_PLACEHOLDER') }}">
+			<input class="button2" name="submit" type="submit" value="{{ lang('SUBMIT') }}">
+			<input type="hidden" name="action" value="add">
+			<input type="hidden" name="forum_id" value="{{ FORUM_ID }}">
 			{{ S_FORM_TOKEN }}
 			{{ S_HIDDEN_FIELDS }}
 		</fieldset>
@@ -68,4 +68,5 @@ <h1>{{ lang('TOPIC_PREFIXES') }}</h1>
 {% endif %}
 
 {% INCLUDEJS '@phpbb_topicprefixes/acp_topic_prefixes.js' %}
+{% INCLUDECSS '@phpbb_topicprefixes/acp_topic_prefixes.css' %}
 {% include 'overall_footer.html' %}
diff --git a/adm/style/acp_topic_prefixes.js b/adm/style/acp_topic_prefixes.js
index 90ba33c..5958e7c 100644
--- a/adm/style/acp_topic_prefixes.js
+++ b/adm/style/acp_topic_prefixes.js
@@ -1,9 +1,8 @@
-(function($) {
-
+(function() {
 	'use strict';
 
-	$('#select_forum').on('change', function() {
-		$(this).closest('form').trigger('submit');
+	document.getElementById('select_forum').addEventListener('change', function() {
+		this.closest('form').submit();
 	});
 
 	phpbb.addAjaxCallback('tp_toggle', function(res) {
@@ -12,8 +11,7 @@
 		}
 
 		const icon = this.querySelector('i');
-		icon.classList.toggle('fa-toggle-on');
-		icon.classList.toggle('fa-toggle-off');
+		icon.classList.toggle('tp-toggle-on');
+		icon.classList.toggle('tp-toggle-off');
 	});
-
-})(jQuery);
+})();
diff --git a/composer.json b/composer.json
index 776d0e7..b08e4bd 100644
--- a/composer.json
+++ b/composer.json
@@ -3,7 +3,7 @@
 	"type": "phpbb-extension",
 	"description": "An official phpBB extension for topic prefixes.",
 	"homepage": "https://www.phpbb.com/customise/db/extension/topicprefixes/",
-	"version": "1.0.1",
+	"version": "1.0.2-dev",
 	"license": "GPL-2.0-only",
 	"authors": [
 		{
@@ -27,7 +27,7 @@
 	"extra": {
 		"display-name": "phpBB Topic Prefixes",
 		"soft-require": {
-			"phpbb/phpbb": ">=3.2.0,<4.0.0@dev"
+			"phpbb/phpbb": ">=3.2.0"
 		},
 		"version-check": {
 			"host": "www.phpbb.com",
diff --git a/controller/admin_controller.php b/controller/admin_controller.php
index c02b29e..d4c1fa5 100644
--- a/controller/admin_controller.php
+++ b/controller/admin_controller.php
@@ -10,6 +10,7 @@
 
 namespace phpbb\topicprefixes\controller;
 
+use phpbb\json_response;
 use phpbb\language\language;
 use phpbb\log\log;
 use phpbb\request\request;
@@ -188,8 +189,7 @@ public function edit_prefix($prefix_id)
 
 		if ($this->request->is_ajax())
 		{
-			$json_response = new \phpbb\json_response;
-			$json_response->send(['success' => true]);
+			$this->send_json_response(true);
 		}
 	}
 
@@ -251,8 +251,7 @@ public function move_prefix($prefix_id, $direction, $amount = 1)
 
 		if ($this->request->is_ajax())
 		{
-			$json_response = new \phpbb\json_response;
-			$json_response->send(['success' => true]);
+			$this->send_json_response(true);
 		}
 	}
 
@@ -334,4 +333,18 @@ protected function get_forum_info($forum_id)
 
 		return $acp_forums->get_forum_info($forum_id);
 	}
+
+	/**
+	 * Send a JSON response
+	 *
+	 * @param bool $content The content of the JSON response (true|false)
+	 * @access protected
+	 */
+	protected function send_json_response($content)
+	{
+		$json_response = new json_response;
+		$json_response->send([
+			'success' => (bool) $content,
+		]);
+	}
 }
diff --git a/ext.php b/ext.php
index 955cff4..9ca695e 100644
--- a/ext.php
+++ b/ext.php
@@ -31,8 +31,6 @@ class ext extends \phpbb\extension\base
 	 */
 	public function is_enableable()
 	{
-		return phpbb_version_compare(PHPBB_VERSION, '3.2.0', '>=')
-			&& phpbb_version_compare(PHPBB_VERSION, '4.0.0-dev', '<')
-			&& PHP_VERSION_ID >= 50400;
+		return phpbb_version_compare(PHPBB_VERSION, '3.2.0', '>=') && PHP_VERSION_ID >= 50400;
 	}
 }
diff --git a/language/en/info_acp_topic_prefixes.php b/language/en/info_acp_topic_prefixes.php
index 0170944..efc4dba 100644
--- a/language/en/info_acp_topic_prefixes.php
+++ b/language/en/info_acp_topic_prefixes.php
@@ -26,6 +26,6 @@
 	'ACP_MANAGE_PREFIXES'	=> 'Manage prefixes',
 
 	// ACP Log messages
-	'ACP_LOG_PREFIX_ADDED'		=> '<strong>Created new topic prefix</strong><br />» %1$s in forum: %2$s',
-	'ACP_LOG_PREFIX_DELETED'	=> '<strong>Deleted topic prefix</strong><br />» %1$s in forum: %2$s',
+	'ACP_LOG_PREFIX_ADDED'		=> '<strong>Created new topic prefix</strong><br>» %1$s in forum: %2$s',
+	'ACP_LOG_PREFIX_DELETED'	=> '<strong>Deleted topic prefix</strong><br>» %1$s in forum: %2$s',
 ));
diff --git a/tests/functional/functional_test.php b/tests/functional/functional_test.php
index 9546238..cfdf7a1 100644
--- a/tests/functional/functional_test.php
+++ b/tests/functional/functional_test.php
@@ -79,11 +79,11 @@ public function test_acp_disable_prefix()
 
 		// Disable the prefix
 		$crawler = self::request('GET', 'adm/index.php?i=\phpbb\topicprefixes\acp\topic_prefixes_module&mode=manage&action=edit&forum_id=' . self::FORUM_ID . "&prefix_id={$prefix}&hash={$hash}&sid={$this->sid}");
-		self::assertCount(1, $crawler->filter('tr')->eq(2)->filter('.fa-toggle-off'));
+		self::assertCount(1, $crawler->filter('tr')->eq(2)->filter('.tp-toggle-off'));
 
 		// Enable the prefix
 		$crawler = self::request('GET', 'adm/index.php?i=\phpbb\topicprefixes\acp\topic_prefixes_module&mode=manage&action=edit&forum_id=' . self::FORUM_ID . "&prefix_id={$prefix}&hash={$hash}&sid={$this->sid}");
-		self::assertCount(1, $crawler->filter('tr')->eq(2)->filter('.fa-toggle-on'));
+		self::assertCount(1, $crawler->filter('tr')->eq(2)->filter('.tp-toggle-on'));
 	}
 
 	public function test_acp_delete_prefix()