diff --git a/apps/theming/appinfo/app.php b/apps/theming/appinfo/app.php
deleted file mode 100644
index 784dad7d94..0000000000
--- a/apps/theming/appinfo/app.php
+++ /dev/null
@@ -1,49 +0,0 @@
-<?php
-/**
- * @copyright Copyright (c) 2016 Bjoern Schiessle <bjoern@schiessle.org>
- * @copyright Copyright (c) 2016 Lukas Reschke <lukas@statuscode.ch>
- *
- * @author Bjoern Schiessle <bjoern@schiessle.org>
- * @author Christoph Wurst <christoph@winzerhof-wurst.at>
- * @author Joas Schilling <coding@schilljs.com>
- * @author Julius Härtl <jus@bitgrid.net>
- * @author Lukas Reschke <lukas@statuscode.ch>
- * @author Robin Appelman <robin@icewind.nl>
- *
- * @license GNU AGPL version 3 or any later version
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-use OCA\Theming\AppInfo\Application;
-
-$app = \OC::$server->query(Application::class);
-$app->getContainer()->registerCapability(\OCA\Theming\Capabilities::class);
-
-$linkToCSS = \OC::$server->getURLGenerator()->linkToRoute(
-	'theming.Theming.getStylesheet',
-	[
-		'v' => \OC::$server->getConfig()->getAppValue('theming', 'cachebuster', '0'),
-	]
-);
-\OCP\Util::addHeader(
-	'link',
-	[
-		'rel' => 'stylesheet',
-		'href' => $linkToCSS,
-	]
-);
-
-\OCP\Util::addScript('theming', 'theming');
diff --git a/apps/theming/lib/AppInfo/Application.php b/apps/theming/lib/AppInfo/Application.php
index 5d722a9627..2fc752f73a 100644
--- a/apps/theming/lib/AppInfo/Application.php
+++ b/apps/theming/lib/AppInfo/Application.php
@@ -2,6 +2,7 @@
 /**
  * @copyright Copyright (c) 2019 Robin Appelman <robin@icewind.nl>
  *
+ * @author Morris Jobke <hey@morrisjobke.de>
  * @author Robin Appelman <robin@icewind.nl>
  * @author Roeland Jago Douma <roeland@famdouma.nl>
  *
@@ -24,28 +25,26 @@
 
 namespace OCA\Theming\AppInfo;
 
-use OCA\Theming\Service\JSDataService;
-use OCP\AppFramework\IAppContainer;
-use OCP\IInitialStateService;
+use OCA\Theming\Capabilities;
+use OCA\Theming\Listener\BeforeTemplateRenderedListener;
+use OCP\AppFramework\App;
+use OCP\AppFramework\Bootstrap\IBootContext;
+use OCP\AppFramework\Bootstrap\IBootstrap;
+use OCP\AppFramework\Bootstrap\IRegistrationContext;
+use OCP\AppFramework\Http\Events\BeforeTemplateRenderedEvent;
 
-class Application extends \OCP\AppFramework\App {
+class Application extends App implements IBootstrap {
 	public const APP_ID = 'theming';
 
 	public function __construct() {
 		parent::__construct(self::APP_ID);
-
-		$container = $this->getContainer();
-		$this->registerInitialState($container);
 	}
 
-	private function registerInitialState(IAppContainer $container) {
-		/** @var IInitialStateService $initialState */
-		$initialState = $container->query(IInitialStateService::class);
+	public function register(IRegistrationContext $context): void {
+		$context->registerCapability(Capabilities::class);
+		$context->registerEventListener(BeforeTemplateRenderedEvent::class, BeforeTemplateRenderedListener::class);
+	}
 
-		$initialState->provideLazyInitialState(self::APP_ID, 'data', function () use ($container) {
-			/** @var JSDataService $data */
-			$data = $container->query(JSDataService::class);
-			return $data;
-		});
+	public function boot(IBootContext $context): void {
 	}
 }
diff --git a/apps/theming/lib/Listener/BeforeTemplateRenderedListener.php b/apps/theming/lib/Listener/BeforeTemplateRenderedListener.php
new file mode 100644
index 0000000000..1d84f4eae8
--- /dev/null
+++ b/apps/theming/lib/Listener/BeforeTemplateRenderedListener.php
@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020 Morris Jobke <hey@morrisjobke.de>
+ *
+ * @author Morris Jobke <hey@morrisjobke.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\Theming\Listener;
+
+use OCA\Theming\AppInfo\Application;
+use OCA\Theming\Service\JSDataService;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\IConfig;
+use OCP\IInitialStateService;
+use OCP\IServerContainer;
+use OCP\IURLGenerator;
+
+class BeforeTemplateRenderedListener implements IEventListener {
+
+	/** @var IInitialStateService */
+	private $initialStateService;
+	/** @var IURLGenerator */
+	private $urlGenerator;
+	/** @var IConfig */
+	private $config;
+	/** @var IServerContainer */
+	private $serverContainer;
+
+	public function __construct(
+		IInitialStateService $initialStateService,
+		IURLGenerator $urlGenerator,
+		IConfig $config,
+		IServerContainer $serverContainer
+	) {
+		$this->initialStateService = $initialStateService;
+		$this->urlGenerator = $urlGenerator;
+		$this->config = $config;
+		$this->serverContainer = $serverContainer;
+	}
+
+	public function handle(Event $event): void {
+		$serverContainer = $this->serverContainer;
+		$this->initialStateService->provideLazyInitialState(Application::APP_ID, 'data', function () use ($serverContainer) {
+			return $serverContainer->query(JSDataService::class);
+		});
+
+		$linkToCSS = $this->urlGenerator->linkToRoute(
+			'theming.Theming.getStylesheet',
+			[
+				'v' => $this->config->getAppValue('theming', 'cachebuster', '0'),
+			]
+		);
+		\OCP\Util::addHeader(
+			'link',
+			[
+				'rel' => 'stylesheet',
+				'href' => $linkToCSS,
+			]
+		);
+
+		\OCP\Util::addScript('theming', 'theming');
+	}
+}