diff --git a/files_opds/ajax/admin.php b/files_opds/ajax/admin.php
index 75f99d7..7a48fa7 100644
--- a/files_opds/ajax/admin.php
+++ b/files_opds/ajax/admin.php
@@ -12,8 +12,8 @@
 
 namespace OCA\Files_Opds;
 
-\OCP\JSON::callCheck();
-\OCP\JSON::checkLoggedIn();
+\OC_JSON::callCheck();
+\OC_JSON::checkLoggedIn();
 $defaults = new \OC_Defaults();
 
 $l = \OC::$server->getL10N('files_opds');
@@ -53,11 +53,10 @@ if (isset($_POST['opdsCoverX'])) {
 	Config::setPreview('OC\Preview\MSOffice2007',$opdsPreviewMsOffice);
 }
 
-\OCP\JSON::success(
+\OC_JSON::success(
 array(
 	'data' => array('message'=> $l->t('Settings updated successfully.'))
 	)
 );
 
 exit();
-
diff --git a/files_opds/ajax/clear_bookshelf.php b/files_opds/ajax/clear_bookshelf.php
index 0ba1604..727a76a 100644
--- a/files_opds/ajax/clear_bookshelf.php
+++ b/files_opds/ajax/clear_bookshelf.php
@@ -14,8 +14,8 @@ namespace OCA\Files_Opds;
 
 $l = \OC::$server->getL10N('files_opds');
 
-\OCP\JSON::checkLoggedIn();
-\OCP\JSON::callCheck();
+\OC_JSON::checkLoggedIn();
+\OC_JSON::callCheck();
 
 Bookshelf::clear();
-\OCP\JSON::success(array( "data" => array( "message" => $l->t("Bookshelf cleared")))); 
+\OC_JSON::success(array( "data" => array( "message" => $l->t("Bookshelf cleared")))); 
diff --git a/files_opds/ajax/personal.php b/files_opds/ajax/personal.php
index 2d019b8..1be74cb 100644
--- a/files_opds/ajax/personal.php
+++ b/files_opds/ajax/personal.php
@@ -12,8 +12,8 @@
 
 namespace OCA\Files_Opds;
 
-\OCP\JSON::callCheck();
-\OCP\JSON::checkLoggedIn();
+\OC_JSON::callCheck();
+\OC_JSON::checkLoggedIn();
 
 $l = \OC::$server->getL10N('files_opds');
 
@@ -21,25 +21,25 @@ $opdsEnable = isset($_POST['opdsEnable']) ? $_POST['opdsEnable'] : 'false';
 $rootPath = isset($_POST['rootPath']) ? $_POST['rootPath'] : '/Library';
 $fileTypes = isset($_POST['fileTypes']) ? $_POST['fileTypes'] : '';
 $skipList = isset($_POST['skipList']) ? $_POST['skipList'] : 'metadata.opf,cover.jpg';
-$feedTitle = isset($_POST['feedTitle']) ? $_POST['feedTitle'] : $l->t("%s's Library", \OCP\User::getDisplayName());
+$feedTitle = isset($_POST['feedTitle']) ? $_POST['feedTitle'] : $l->t("%s's Library", \OC_User::getDisplayName());
 
 if (!strlen($rootPath) ||
-    \OC\Files\Filesystem::isValidPath($rootPath) === false || 
+    \OC\Files\Filesystem::isValidPath($rootPath) === false ||
     \OC\Files\Filesystem::file_exists($rootPath) === false ) {
-	\OCP\JSON::error(
+	\OC_JSON::error(
 		array(
 			'data' => array('message'=> $l->t('Directory does not exist!'))
 		)
 	);
 } else {
 	Config::set('root_path', $rootPath);
-        Config::set('enable', $opdsEnable);
-        Config::set('file_types', $fileTypes);
-        Config::set('skip_list', $skipList);
-        Config::set('feed_title', $feedTitle);
+	Config::set('enable', $opdsEnable);
+	Config::set('file_types', $fileTypes);
+	Config::set('skip_list', $skipList);
+	Config::set('feed_title', $feedTitle);
 	Config::set('id', Util::genUuid());
 
-       	\OCP\JSON::success(
+       	\OC_JSON::success(
 	array(
 		'data' => array('message'=> $l->t('Settings updated successfully.'))
 		)
@@ -47,4 +47,3 @@ if (!strlen($rootPath) ||
 }
 
 exit();
-
diff --git a/files_opds/ajax/schedule_rescan.php b/files_opds/ajax/schedule_rescan.php
index 0f266c3..5d91c3e 100644
--- a/files_opds/ajax/schedule_rescan.php
+++ b/files_opds/ajax/schedule_rescan.php
@@ -14,8 +14,8 @@ namespace OCA\Files_Opds;
 
 $l = \OC::$server->getL10N('files_opds');
 
-\OCP\JSON::checkLoggedIn();
-\OCP\JSON::callCheck();
+\OC_JSON::checkLoggedIn();
+\OC_JSON::callCheck();
 
 Meta::rescan();
-\OCP\JSON::success(array( "data" => array( "message" => $l->t("Rescan scheduled")))); 
+\OC_JSON::success(array( "data" => array( "message" => $l->t("Rescan scheduled")))); 
diff --git a/files_opds/appinfo/info.xml b/files_opds/appinfo/info.xml
index 699df24..e4e3cd8 100644
--- a/files_opds/appinfo/info.xml
+++ b/files_opds/appinfo/info.xml
@@ -37,7 +37,7 @@ See [README] for more information on (mis)features of this app.
             <database>sqlite</database>
             <database>mysql</database>
             <owncloud min-version="8.2" max-version="10.0" />
-            <nextcloud min-version="8.1" max-version="13.0" />
+            <nextcloud min-version="8.1" max-version="14.0" />
         </dependencies>
 	<settings>
 		<admin>OCA\Files_Opds\Settings\Admin</admin>
diff --git a/files_opds/lib/config.php b/files_opds/lib/config.php
index 6e84a54..a468767 100644
--- a/files_opds/lib/config.php
+++ b/files_opds/lib/config.php
@@ -25,7 +25,7 @@ class Config
 	 * @return string retrieved value or default
 	 */
 	public static function get($key, $default) {
-		return \OCP\Config::getUserValue(\OCP\User::getUser(), 'files_opds', $key, $default);
+		return \OC::$server->getConfig()->getUserValue(\OC::$server->getUserSession()->getUser()->getUID(), 'files_opds', $key, $default);
 	}
 
 	/**
@@ -36,7 +36,7 @@ class Config
 	 * @return bool success
 	 */
 	public static function set($key, $value) {
-		return \OCP\Config::setUserValue(\OCP\User::getUser(), 'files_opds', $key, $value);
+		return \OC::$server->getConfig()->setUserValue(\OC::$server->getUserSession()->getUser()->getUID(), 'files_opds', $key, $value);
 	}
 
 	/**
@@ -47,7 +47,7 @@ class Config
 	 * @return string retrieved value or default
 	 */
 	public static function getApp($key, $default) {
-		return \OCP\Config::getAppValue('files_opds', $key, $default);
+		return \OC::$server->getConfig()->getAppValue('files_opds', $key, $default);
 	}
 
 	/**
@@ -58,17 +58,17 @@ class Config
 	 * @return bool success
 	 */
 	public static function setApp($key, $value) {
-		return \OCP\Config::setAppValue('files_opds', $key, $value);
+		return \OC::$server->getConfig()->setAppValue('files_opds', $key, $value);
 	}
-	
+
 	/**
 	 * @brief get preview status
-	 * 
+	 *
 	 * @param string format
 	 * @return bool (true = enabled, false = disabled)
 	 */
 	public static function getPreview($format) {
-		$enablePreviewProviders = \OCP\Config::getSystemValue('enabledPreviewProviders', null);
+		$enablePreviewProviders = \OC::$server->getConfig()->getSystemValue('enabledPreviewProviders', null);
 		if (!($enablePreviewProviders === null)) {
 			return in_array($format, $enablePreviewProviders);
 		}
@@ -83,7 +83,7 @@ class Config
 	 * @return bool
 	 */
 	public static function setPreview($format, $enable = 'false') {
-		$enablePreviewProviders = \OCP\Config::getSystemValue('enabledPreviewProviders', null);
+		$enablePreviewProviders = \OC::$server->getConfig()->getSystemValue('enabledPreviewProviders', null);
 		if ($enable == 'true') {
 			if ($enablePreviewProviders === null) {
 				// set up default providers
@@ -103,7 +103,7 @@ class Config
 			}
 		}
 
-		if (!(\OCP\Config::setSystemValue('enabledPreviewProviders', $enablePreviewProviders))) {
+		if (!(\OC::$server->getConfig()->setSystemValue('enabledPreviewProviders', $enablePreviewProviders))) {
 			logWarn("Failed to enable " . $format . " preview provider (config.php readonly?)");
 			return true;
 		}
diff --git a/files_opds/lib/feed.php b/files_opds/lib/feed.php
index 493764c..3cf127a 100644
--- a/files_opds/lib/feed.php
+++ b/files_opds/lib/feed.php
@@ -24,7 +24,7 @@ class Feed
          * @return string feed id
          */
         public static function getFeedId() {
-                return Config::get('id', '');
+		return Config::get('id', '');
         }
 
         /**
@@ -66,8 +66,8 @@ class Feed
                 $tmpl->assign('id', $id);
                 $tmpl->assign('type', $type);
                 $tmpl->assign('dir', $dir);
-                $tmpl->assign('user', \OCP\User::getDisplayName());
-                $tmpl->assign('feed_title', Config::get('feed_title',\OCP\User::getDisplayName() . "'s Library"));
+                $tmpl->assign('user', \OC_User::getDisplayName());
+                $tmpl->assign('feed_title', Config::get('feed_title',\OC_User::getDisplayName() . "'s Library"));
                 $tmpl->assign('feed_subtitle', Config::getApp('feed_subtitle', $defaults->getName() . " OPDS catalog"));
                 $tmpl->assign('feed_updated', time());
                 $tmpl->printPage();
diff --git a/files_opds/lib/meta.php b/files_opds/lib/meta.php
index a3c12cb..bb4aaa6 100644
--- a/files_opds/lib/meta.php
+++ b/files_opds/lib/meta.php
@@ -64,7 +64,7 @@ class Meta
 	protected static function load($id) {
                 $sql = 'SELECT * FROM `*PREFIX*opds_metadata` WHERE id = ?';
                 $args = array($id);
-                $query = \OCP\DB::prepare($sql);
+                $query = \OC_DB::prepare($sql);
                 $result = $query->execute($args);
 
 		return ($row = $result->fetchRow()) ? $row : false;
@@ -79,7 +79,7 @@ class Meta
 	protected static function save($meta) {
 		$sql = "SELECT `id` FROM *PREFIX*opds_metadata WHERE `id`=?";
 		$args = array($meta['id']);
-		$query = \OCP\DB::prepare($sql);
+		$query = \OC_DB::prepare($sql);
 		$result = $query->execute($args);
 		$data = $result->fetchRow();
 		if (isset($data['id'])) {
@@ -118,7 +118,7 @@ class Meta
 				$meta['rescan']
 				);
 		}
-		$query = \OCP\DB::prepare($sql);
+		$query = \OC_DB::prepare($sql);
 
 		return $query->execute($args);
 	}
@@ -150,7 +150,7 @@ class Meta
 	public static function remove($id) {
 		$sql = "DELETE FROM *PREFIX*opds_metadata WHERE `id`=?";
 		$args = array($id);
-		$query = \OCP\DB::prepare($sql);
+		$query = \OC_DB::prepare($sql);
 
 		return $query->execute($args);
 	}
@@ -162,7 +162,7 @@ class Meta
 	public static function rescan() {
                 $sql = "UPDATE *PREFIX*opds_metadata SET `rescan`=?";
                 $args = array(date("Y-m-d H:i:s"));
-                $query = \OCP\DB::prepare($sql);
+                $query = \OC_DB::prepare($sql);
                 $result = $query->execute($args);
 	}
 
diff --git a/files_opds/lib/util.php b/files_opds/lib/util.php
index b33cafe..c771c1a 100644
--- a/files_opds/lib/util.php
+++ b/files_opds/lib/util.php
@@ -113,7 +113,7 @@ class Util
 	 */
 	public static function genUuid() {
 		$defaults = new \OC_Defaults();
-		$hash = md5(\OCP\User::getDisplayName() . $defaults->getBaseUrl());
+		$hash = md5(\OC_User::getDisplayName() . $defaults->getBaseUrl());
 		$hash = substr($hash, 0, 8 ) .'-'.
 			substr($hash, 8, 4) .'-3'.
 			substr($hash, 13, 3) .'-9'.
diff --git a/files_opds/personal.php b/files_opds/personal.php
index 5fac311..79593ba 100644
--- a/files_opds/personal.php
+++ b/files_opds/personal.php
@@ -23,7 +23,7 @@ $tmpl->assign('opdsEnable-value', ($opdsEnable === 'true') ? '1' : '0');
 $tmpl->assign('rootPath', Config::get('root_path', '/Library'));
 $tmpl->assign('fileTypes', Config::get('file_types', ''));
 $tmpl->assign('skipList', Config::get('skip_list', 'metadata.opf,cover.jpg'));
-$tmpl->assign('feedTitle', Config::get('feed_title', $l->t("%s's Library", \OCP\User::getDisplayName())));
+$tmpl->assign('feedTitle', Config::get('feed_title', $l->t("%s's Library", \OC_User::getDisplayName())));
 $tmpl->assign('bookshelf-count', Bookshelf::count());
 $tmpl->assign('feedUrl', Util::linkToAbsolute('','index.php') . '/apps/files_opds/');