diff --git a/apps/dav/lib/Connector/Sabre/MaintenancePlugin.php b/apps/dav/lib/Connector/Sabre/MaintenancePlugin.php
index 36110c81db9..9c5946481b6 100644
--- a/apps/dav/lib/Connector/Sabre/MaintenancePlugin.php
+++ b/apps/dav/lib/Connector/Sabre/MaintenancePlugin.php
@@ -78,7 +78,7 @@ class MaintenancePlugin extends ServerPlugin {
 	 * @return bool
 	 */
 	public function checkMaintenanceMode() {
-		if ($this->config->getSystemValue('maintenance', false)) {
+		if ($this->config->getSystemValueBool('maintenance')) {
 			throw new ServiceUnavailable('System in maintenance mode.');
 		}
 		if (Util::needUpgrade()) {
diff --git a/apps/encryption/lib/AppInfo/Application.php b/apps/encryption/lib/AppInfo/Application.php
index 55839e097a1..5846a01db13 100644
--- a/apps/encryption/lib/AppInfo/Application.php
+++ b/apps/encryption/lib/AppInfo/Application.php
@@ -75,7 +75,7 @@ class Application extends \OCP\AppFramework\App {
 	 * register hooks
 	 */
 	public function registerHooks() {
-		if (!$this->config->getSystemValue('maintenance', false)) {
+		if (!$this->config->getSystemValueBool('maintenance')) {
 
 			$container = $this->getContainer();
 			$server = $container->getServer();
diff --git a/core/Command/Encryption/DecryptAll.php b/core/Command/Encryption/DecryptAll.php
index 253223f9529..6ae90196963 100644
--- a/core/Command/Encryption/DecryptAll.php
+++ b/core/Command/Encryption/DecryptAll.php
@@ -89,7 +89,7 @@ class DecryptAll extends Command {
 	 */
 	protected function forceMaintenanceAndTrashbin() {
 		$this->wasTrashbinEnabled = $this->appManager->isEnabledForUser('files_trashbin');
-		$this->wasMaintenanceModeEnabled = $this->config->getSystemValue('maintenance', false);
+		$this->wasMaintenanceModeEnabled = $this->config->getSystemValueBool('maintenance');
 		$this->config->setSystemValue('maintenance', true);
 		$this->appManager->disableApp('files_trashbin');
 	}
diff --git a/core/Command/Encryption/EncryptAll.php b/core/Command/Encryption/EncryptAll.php
index b16fa0af2c7..7a257aac201 100644
--- a/core/Command/Encryption/EncryptAll.php
+++ b/core/Command/Encryption/EncryptAll.php
@@ -78,7 +78,7 @@ class EncryptAll extends Command {
 	 */
 	protected function forceMaintenanceAndTrashbin() {
 		$this->wasTrashbinEnabled = $this->appManager->isEnabledForUser('files_trashbin');
-		$this->wasMaintenanceModeEnabled = $this->config->getSystemValue('maintenance', false);
+		$this->wasMaintenanceModeEnabled = $this->config->getSystemValueBool('maintenance');
 		$this->config->setSystemValue('maintenance', true);
 		$this->appManager->disableApp('files_trashbin');
 	}
diff --git a/core/Command/Maintenance/Mode.php b/core/Command/Maintenance/Mode.php
index db4c9dc8c0b..1692eb08d87 100644
--- a/core/Command/Maintenance/Mode.php
+++ b/core/Command/Maintenance/Mode.php
@@ -59,7 +59,7 @@ class Mode extends Command {
 	}
 
 	protected function execute(InputInterface $input, OutputInterface $output) {
-		$maintenanceMode = $this->config->getSystemValue('maintenance', false);
+		$maintenanceMode = $this->config->getSystemValueBool('maintenance');
 		if ($input->getOption('on')) {
 			if ($maintenanceMode === false) {
 				$this->config->setSystemValue('maintenance', true);
diff --git a/core/Command/Maintenance/Repair.php b/core/Command/Maintenance/Repair.php
index e9595a22285..460bc6880c1 100644
--- a/core/Command/Maintenance/Repair.php
+++ b/core/Command/Maintenance/Repair.php
@@ -106,7 +106,7 @@ class Repair extends Command {
 			}
 		}
 
-		$maintenanceMode = $this->config->getSystemValue('maintenance', false);
+		$maintenanceMode = $this->config->getSystemValueBool('maintenance');
 		$this->config->setSystemValue('maintenance', true);
 
 		$this->progress = new ProgressBar($output);
diff --git a/core/Command/Upgrade.php b/core/Command/Upgrade.php
index 5a2deea0b6c..2d7ec4f688d 100644
--- a/core/Command/Upgrade.php
+++ b/core/Command/Upgrade.php
@@ -180,7 +180,7 @@ class Upgrade extends Command {
 			$dispatcher->addListener('\OC\Repair::info', $repairListener);
 			$dispatcher->addListener('\OC\Repair::warning', $repairListener);
 			$dispatcher->addListener('\OC\Repair::error', $repairListener);
-			
+
 
 			$updater->listen('\OC\Updater', 'maintenanceEnabled', function () use($output) {
 				$output->writeln('<info>Turned on maintenance mode</info>');
@@ -264,7 +264,7 @@ class Upgrade extends Command {
 			}
 
 			return self::ERROR_SUCCESS;
-		} else if($this->config->getSystemValue('maintenance', false)) {
+		} else if($this->config->getSystemValueBool('maintenance')) {
 			//Possible scenario: Nextcloud core is updated but an app failed
 			$output->writeln('<warning>Nextcloud is in maintenance mode</warning>');
 			$output->write('<comment>Maybe an upgrade is already in process. Please check the '
diff --git a/cron.php b/cron.php
index b79c40d2a72..cdfa0fb367d 100644
--- a/cron.php
+++ b/cron.php
@@ -44,7 +44,7 @@ try {
 		\OC::$server->getLogger()->debug('Update required, skipping cron', ['app' => 'cron']);
 		exit;
 	}
-	if (\OC::$server->getSystemConfig()->getValue('maintenance', false)) {
+	if ((bool) \OC::$server->getSystemConfig()->getValue('maintenance', false)) {
 		\OC::$server->getLogger()->debug('We are in maintenance mode, skipping cron', ['app' => 'cron']);
 		exit;
 	}
diff --git a/lib/base.php b/lib/base.php
index 90fa5496200..d5149fc0449 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -285,7 +285,7 @@ class OC {
 
 	public static function checkMaintenanceMode() {
 		// Allow ajax update script to execute without being stopped
-		if (\OC::$server->getSystemConfig()->getValue('maintenance', false) && OC::$SUBURI != '/core/ajax/update.php') {
+		if (((bool) \OC::$server->getSystemConfig()->getValue('maintenance', false)) && OC::$SUBURI != '/core/ajax/update.php') {
 			// send http status 503
 			http_response_code(503);
 			header('Retry-After: 120');
@@ -938,7 +938,7 @@ class OC {
 				if (function_exists('opcache_reset')) {
 					opcache_reset();
 				}
-				if (!$systemConfig->getValue('maintenance', false)) {
+				if (!((bool) $systemConfig->getValue('maintenance', false))) {
 					self::printUpgradePage($systemConfig);
 					exit();
 				}
@@ -966,7 +966,7 @@ class OC {
 
 		// Load minimum set of apps
 		if (!\OCP\Util::needUpgrade()
-			&& !$systemConfig->getValue('maintenance', false)) {
+			&& !((bool) $systemConfig->getValue('maintenance', false))) {
 			// For logged-in users: Load everything
 			if(\OC::$server->getUserSession()->isLoggedIn()) {
 				OC_App::loadApps();
@@ -979,7 +979,7 @@ class OC {
 
 		if (!self::$CLI) {
 			try {
-				if (!$systemConfig->getValue('maintenance', false) && !\OCP\Util::needUpgrade()) {
+				if (!((bool) $systemConfig->getValue('maintenance', false)) && !\OCP\Util::needUpgrade()) {
 					OC_App::loadApps(array('filesystem', 'logging'));
 					OC_App::loadApps();
 				}
diff --git a/lib/private/Console/Application.php b/lib/private/Console/Application.php
index 0e30fa02b94..d7c047527f1 100644
--- a/lib/private/Console/Application.php
+++ b/lib/private/Console/Application.php
@@ -91,10 +91,10 @@ class Application {
 		$inputDefinition = $application->getDefinition();
 		$inputDefinition->addOption(
 			new InputOption(
-				'no-warnings', 
-				null, 
-				InputOption::VALUE_NONE, 
-				'Skip global warnings, show command output only', 
+				'no-warnings',
+				null,
+				InputOption::VALUE_NONE,
+				'Skip global warnings, show command output only',
 				null
 			)
 		);
@@ -119,7 +119,7 @@ class Application {
 			if ($this->config->getSystemValue('installed', false)) {
 				if (\OCP\Util::needUpgrade()) {
 					throw new NeedsUpdateException();
-				} elseif ($this->config->getSystemValue('maintenance', false)) {
+				} elseif ($this->config->getSystemValueBool('maintenance')) {
 					$this->writeMaintenanceModeInfo($input, $output);
 				} else {
 					OC_App::loadApps();
diff --git a/lib/private/Route/Router.php b/lib/private/Route/Router.php
index b44b3f7c2ce..1839b356424 100644
--- a/lib/private/Route/Router.php
+++ b/lib/private/Route/Router.php
@@ -260,7 +260,7 @@ class Router implements IRouter {
 			$this->loadRoutes($app);
 		} else if (substr($url, 0, 6) === '/core/' or substr($url, 0, 10) === '/settings/') {
 			\OC::$REQUESTEDAPP = $url;
-			if (!\OC::$server->getConfig()->getSystemValue('maintenance', false) && !Util::needUpgrade()) {
+			if (!\OC::$server->getConfig()->getSystemValueBool('maintenance') && !Util::needUpgrade()) {
 				\OC_App::loadApps();
 			}
 			$this->loadRoutes('core');
diff --git a/lib/private/Updater.php b/lib/private/Updater.php
index 4b4723be94f..313cfc82ffa 100644
--- a/lib/private/Updater.php
+++ b/lib/private/Updater.php
@@ -104,7 +104,7 @@ class Updater extends BasicEmitter {
 		$this->emit('\OC\Updater', 'setDebugLogLevel', [ $logLevel, $this->logLevelNames[$logLevel] ]);
 		$this->config->setSystemValue('loglevel', ILogger::DEBUG);
 
-		$wasMaintenanceModeEnabled = $this->config->getSystemValue('maintenance', false);
+		$wasMaintenanceModeEnabled = $this->config->getSystemValueBool('maintenance');
 
 		if(!$wasMaintenanceModeEnabled) {
 			$this->config->setSystemValue('maintenance', true);
@@ -614,4 +614,3 @@ class Updater extends BasicEmitter {
 	}
 
 }
-
diff --git a/lib/private/legacy/app.php b/lib/private/legacy/app.php
index 4cab92eba64..9b4a83de349 100644
--- a/lib/private/legacy/app.php
+++ b/lib/private/legacy/app.php
@@ -106,7 +106,7 @@ class OC_App {
 	 * if $types is set to non-empty array, only apps of those types will be loaded
 	 */
 	public static function loadApps(array $types = []): bool {
-		if (\OC::$server->getSystemConfig()->getValue('maintenance', false)) {
+		if ((bool) \OC::$server->getSystemConfig()->getValue('maintenance', false)) {
 			return false;
 		}
 		// Load the enabled apps here
diff --git a/ocs/v1.php b/ocs/v1.php
index 36749f44c1b..4e50392e752 100644
--- a/ocs/v1.php
+++ b/ocs/v1.php
@@ -33,7 +33,7 @@ require_once __DIR__ . '/../lib/versioncheck.php';
 require_once __DIR__ . '/../lib/base.php';
 
 if (\OCP\Util::needUpgrade()
-	|| \OC::$server->getSystemConfig()->getValue('maintenance', false)) {
+	|| \OC::$server->getConfig()->getSystemValueBool('maintenance')) {
 	// since the behavior of apps or remotes are unpredictable during
 	// an upgrade, return a 503 directly
 	http_response_code(503);
@@ -103,4 +103,3 @@ try {
 		.' http://www.freedesktop.org/wiki/Specifications/open-collaboration-services.'."\n";
 	OC_API::respond(new \OC\OCS\Result(null, \OCP\API::RESPOND_NOT_FOUND, $txt), $format);
 }
-