diff --git a/apps/updatenotification/tests/ResetTokenBackgroundJobTest.php b/apps/updatenotification/tests/ResetTokenBackgroundJobTest.php
index 129ba37098063..e1fce2ad831dc 100644
--- a/apps/updatenotification/tests/ResetTokenBackgroundJobTest.php
+++ b/apps/updatenotification/tests/ResetTokenBackgroundJobTest.php
@@ -65,13 +65,11 @@ public function testRunWithNotExpiredToken() {
 
 	public function testRunWithExpiredToken() {
 		$this->timeFactory
-			->expects($this->at(0))
 			->method('getTime')
-			->willReturn(1455131633);
-		$this->timeFactory
-			->expects($this->at(1))
-			->method('getTime')
-			->willReturn(1455045234);
+			->willReturnOnConsecutiveCalls(
+				1455131633,
+				1455045234
+			);
 		$this->config
 			->expects($this->once())
 			->method('getAppValue')
diff --git a/apps/updatenotification/tests/Settings/AdminTest.php b/apps/updatenotification/tests/Settings/AdminTest.php
index 852504fb45aa4..bbaa56fa18dcf 100644
--- a/apps/updatenotification/tests/Settings/AdminTest.php
+++ b/apps/updatenotification/tests/Settings/AdminTest.php
@@ -29,6 +29,7 @@
  */
 namespace OCA\UpdateNotification\Tests\Settings;
 
+use OC\User\Backend;
 use OCA\UpdateNotification\Settings\Admin;
 use OCA\UpdateNotification\UpdateChecker;
 use OCP\AppFramework\Http\TemplateResponse;
@@ -36,13 +37,18 @@
 use OCP\IDateTimeFormatter;
 use OCP\IGroup;
 use OCP\IGroupManager;
+use OCP\IUserManager;
 use OCP\L10N\IFactory;
 use OCP\L10N\ILanguageIterator;
 use OCP\Support\Subscription\IRegistry;
+use OCP\User\Backend\ICountUsersBackend;
+use OCP\UserInterface;
 use OCP\Util;
-use Test\TestCase;
-use OCP\IUserManager;
 use Psr\Log\LoggerInterface;
+use Test\TestCase;
+
+interface UserInterfaceAwareICountUsersBackend extends UserInterface, ICountUsersBackend {
+}
 
 class AdminTest extends TestCase {
 	/** @var IFactory|\PHPUnit\Framework\MockObject\MockObject */
@@ -77,11 +83,11 @@ protected function setUp(): void {
 		$this->logger = $this->createMock(LoggerInterface::class);
 
 		$this->admin = new Admin(
-			$this->config, 
-			$this->updateChecker, 
-			$this->groupManager, 
-			$this->dateTimeFormatter, 
-			$this->l10nFactory, 
+			$this->config,
+			$this->updateChecker,
+			$this->groupManager,
+			$this->dateTimeFormatter,
+			$this->l10nFactory,
 			$this->subscriptionRegistry,
 			$this->userManager,
 			$this->logger
@@ -89,9 +95,9 @@ protected function setUp(): void {
 	}
 
 	public function testGetFormWithUpdate() {
-		$backend1 = $this->createMock(UserInterface::class);
-		$backend2 = $this->createMock(UserInterface::class);
-		$backend3 = $this->createMock(UserInterface::class);
+		$backend1 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
+		$backend2 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
+		$backend3 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
 		$backend1
 			->expects($this->once())
 			->method('implementsActions')
@@ -213,9 +219,9 @@ public function testGetFormWithUpdate() {
 	}
 
 	public function testGetFormWithUpdateAndChangedUpdateServer() {
-		$backend1 = $this->createMock(UserInterface::class);
-		$backend2 = $this->createMock(UserInterface::class);
-		$backend3 = $this->createMock(UserInterface::class);
+		$backend1 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
+		$backend2 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
+		$backend3 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
 		$backend1
 			->expects($this->once())
 			->method('implementsActions')
@@ -337,9 +343,9 @@ public function testGetFormWithUpdateAndChangedUpdateServer() {
 	}
 
 	public function testGetFormWithUpdateAndCustomersUpdateServer() {
-		$backend1 = $this->createMock(UserInterface::class);
-		$backend2 = $this->createMock(UserInterface::class);
-		$backend3 = $this->createMock(UserInterface::class);
+		$backend1 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
+		$backend2 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
+		$backend3 = $this->createMock(UserInterfaceAwareICountUsersBackend::class);
 		$backend1
 			->expects($this->once())
 			->method('implementsActions')
diff --git a/lib/private/Encryption/Util.php b/lib/private/Encryption/Util.php
index 174af2e8b8995..541a4ed24f532 100644
--- a/lib/private/Encryption/Util.php
+++ b/lib/private/Encryption/Util.php
@@ -37,6 +37,7 @@
 use OCP\Encryption\IEncryptionModule;
 use OCP\IConfig;
 use OCP\IUser;
+use OCP\App\IAppManager;
 
 class Util {
 	public const HEADER_START = 'HBEGIN';
@@ -299,7 +300,8 @@ public function getUserWithAccessToMountPoint($users, $groups) {
 	 * @return boolean
 	 */
 	public function isSystemWideMountPoint($path, $uid) {
-		if (\OCP\App::isEnabled("files_external")) {
+		$appManager = \OC::$server->get(IAppManager::class);
+		if ($appManager->isEnabledForUser('files_external', null)) {
 			/** @var GlobalStoragesService $storageService */
 			$storageService = \OC::$server->get(GlobalStoragesService::class);
 			$storages = $storageService->getAllStorages();
diff --git a/tests/lib/Encryption/UtilTest.php b/tests/lib/Encryption/UtilTest.php
index 02155be11ddab..ab6101b7027a9 100644
--- a/tests/lib/Encryption/UtilTest.php
+++ b/tests/lib/Encryption/UtilTest.php
@@ -4,8 +4,7 @@
 
 use OC\Encryption\Util;
 use OC\Files\View;
-use OCA\Files_External\Lib\StorageConfig;
-use OCA\Files_External\Service\GlobalStoragesService;
+use OCP\App\IAppManager;
 use OCP\Encryption\IEncryptionModule;
 use OCP\IConfig;
 use Test\TestCase;
@@ -40,11 +39,11 @@ protected function setUp(): void {
 			->disableOriginalConstructor()
 			->getMock();
 
-		$this->userManager = $this->getMockBuilder('OC\User\Manager')
+		$this->userManager = $this->getMockBuilder(\OC\User\Manager::class)
 			->disableOriginalConstructor()
 			->getMock();
 
-		$this->groupManager = $this->getMockBuilder('OC\Group\Manager')
+		$this->groupManager = $this->getMockBuilder(\OC\Group\Manager::class)
 			->disableOriginalConstructor()
 			->getMock();
 
@@ -207,6 +206,15 @@ public function dataTestIsSystemWideMountPoint() {
 	 * @dataProvider dataTestIsSystemWideMountPoint
 	 */
 	public function testIsSystemWideMountPoint($expectedResult, $expectationText, $applicableUsers, $applicableGroups, $mountPointName = '/mp') {
+		$appManager = $this->createMock(IAppManager::class);
+		$appManager
+			->expects($this->once())
+			->method('isEnabledForUser')
+			->with('files_external')
+			->willReturn(true);
+
+		$this->overwriteService(IAppManager::class, $appManager);
+
 		$this->groupManager->method('isInGroup')
 			 ->will($this->returnValueMap([
 			 	['user1', 'group1', true], // user is only in group1
@@ -215,17 +223,28 @@ public function testIsSystemWideMountPoint($expectedResult, $expectationText, $a
 
 		$storages = [];
 
-		$storageConfig = $this->createMock(StorageConfig::class);
+		// StorageConfig
+		$storageConfig = $this->getMockBuilder('OCA\\Files_External\\Lib\\StorageConfig')
+			->setMethods([
+				'getMountPoint',
+				'getApplicableUsers',
+				'getApplicableGroups',
+			])
+			->getMock();
 		$storageConfig->method('getMountPoint')->willReturn($mountPointName);
 		$storageConfig->method('getApplicableUsers')->willReturn($applicableUsers);
 		$storageConfig->method('getApplicableGroups')->willReturn($applicableGroups);
 		$storages[] = $storageConfig;
 
-		$storagesServiceMock = $this->createMock(GlobalStoragesService::class);
+		$storagesServiceMock = $this->getMockBuilder('OCA\\Files_External\\Service\\GlobalStoragesService')
+			->setMethods([
+				'getAllStorages',
+			])
+			->getMock();
 		$storagesServiceMock->expects($this->atLeastOnce())->method('getAllStorages')
 			->willReturn($storages);
 
-		$this->overwriteService(GlobalStoragesService::class, $storagesServiceMock);
+		$this->overwriteService('OCA\\Files_External\\Service\\GlobalStoragesService', $storagesServiceMock);
 
 		$this->assertEquals($expectedResult, $this->util->isSystemWideMountPoint('/files/mp', 'user1'), 'Test case: ' . $expectationText);
 	}
diff --git a/tests/lib/Files/Node/FolderTest.php b/tests/lib/Files/Node/FolderTest.php
index 4cda92b6e838b..1419b4eb0370c 100644
--- a/tests/lib/Files/Node/FolderTest.php
+++ b/tests/lib/Files/Node/FolderTest.php
@@ -105,11 +105,14 @@ public function testGet() {
 			->method('getUser')
 			->willReturn($this->user);
 
+		$expected = $this->createMock(Node::class);
 		$root->method('get')
-			->with('/bar/foo/asd');
+			->with('/bar/foo/asd')
+			->willReturn($expected);
 
 		$node = new Folder($root, $view, '/bar/foo');
-		$node->get('asd');
+		$return = $node->get('asd');
+		self::assertEquals($expected, $return);
 	}
 
 	public function testNodeExists() {
diff --git a/tests/phpunit-autotest.xml b/tests/phpunit-autotest.xml
index d2d45b50db7d7..95664ddae3bc1 100644
--- a/tests/phpunit-autotest.xml
+++ b/tests/phpunit-autotest.xml
@@ -2,6 +2,8 @@
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 bootstrap="bootstrap.php"
 		 verbose="true"
+		 failOnRisky="true"
+		 failOnWarning="true"
 		 backupGlobals="false"
 		 timeoutForSmallTests="900"
 		 timeoutForMediumTests="900"