diff --git a/apps/files_external/appinfo/application.php b/apps/files_external/appinfo/application.php
index 0c8b90935d..c755b6a29b 100644
--- a/apps/files_external/appinfo/application.php
+++ b/apps/files_external/appinfo/application.php
@@ -26,6 +26,7 @@
 namespace OCA\Files_External\AppInfo;
 
 use \OCP\AppFramework\App;
+use OCP\AppFramework\IAppContainer;
 use \OCP\IContainer;
 use \OCA\Files_External\Service\BackendService;
 
@@ -33,9 +34,13 @@ use \OCA\Files_External\Service\BackendService;
  * @package OCA\Files_External\Appinfo
  */
 class Application extends App {
-	public function __construct(array $urlParams=array()) {
+	public function __construct(array $urlParams = array()) {
 		parent::__construct('files_external', $urlParams);
 
+		$this->getContainer()->registerService('OCP\Files\Config\IUserMountCache', function (IAppContainer $c) {
+			return $c->getServer()->query('UserMountCache');
+		});
+
 		$this->loadBackends();
 		$this->loadAuthMechanisms();
 
diff --git a/apps/files_external/migration/storagemigrator.php b/apps/files_external/migration/storagemigrator.php
index 2da47decf9..ba81810a4f 100644
--- a/apps/files_external/migration/storagemigrator.php
+++ b/apps/files_external/migration/storagemigrator.php
@@ -29,6 +29,7 @@ use OCA\Files_external\Service\LegacyStoragesService;
 use OCA\Files_external\Service\StoragesService;
 use OCA\Files_external\Service\UserLegacyStoragesService;
 use OCA\Files_external\Service\UserStoragesService;
+use OCP\Files\Config\IUserMountCache;
 use OCP\IConfig;
 use OCP\IDBConnection;
 use OCP\ILogger;
@@ -64,6 +65,9 @@ class StorageMigrator {
 	 */
 	private $logger;
 
+	/** @var IUserMountCache  */
+	private $userMountCache;
+
 	/**
 	 * StorageMigrator constructor.
 	 *
@@ -72,19 +76,22 @@ class StorageMigrator {
 	 * @param IConfig $config
 	 * @param IDBConnection $connection
 	 * @param ILogger $logger
+	 * @param IUserMountCache $userMountCache
 	 */
 	public function __construct(
 		BackendService $backendService,
 		DBConfigService $dbConfig,
 		IConfig $config,
 		IDBConnection $connection,
-		ILogger $logger
+		ILogger $logger,
+		IUserMountCache $userMountCache
 	) {
 		$this->backendService = $backendService;
 		$this->dbConfig = $dbConfig;
 		$this->config = $config;
 		$this->connection = $connection;
 		$this->logger = $logger;
+		$this->userMountCache = $userMountCache;
 	}
 
 	private function migrate(LegacyStoragesService $legacyService, StoragesService $storageService) {
@@ -107,7 +114,7 @@ class StorageMigrator {
 	 */
 	public function migrateGlobal() {
 		$legacyService = new GlobalLegacyStoragesService($this->backendService);
-		$storageService = new GlobalStoragesService($this->backendService, $this->dbConfig);
+		$storageService = new GlobalStoragesService($this->backendService, $this->dbConfig, $this->userMountCache);
 
 		$this->migrate($legacyService, $storageService);
 	}
@@ -125,7 +132,7 @@ class StorageMigrator {
 		if (version_compare($userVersion, '0.5.0', '<')) {
 			$this->config->setUserValue($userId, 'files_external', 'config_version', '0.5.0');
 			$legacyService = new UserLegacyStoragesService($this->backendService, $dummySession);
-			$storageService = new UserStoragesService($this->backendService, $this->dbConfig, $dummySession);
+			$storageService = new UserStoragesService($this->backendService, $this->dbConfig, $dummySession, $this->userMountCache);
 
 			$this->migrate($legacyService, $storageService);
 		}
diff --git a/apps/files_external/service/storagesservice.php b/apps/files_external/service/storagesservice.php
index c0dd263ed6..678b91c010 100644
--- a/apps/files_external/service/storagesservice.php
+++ b/apps/files_external/service/storagesservice.php
@@ -31,6 +31,7 @@ use \OCA\Files_external\Lib\StorageConfig;
 use \OCA\Files_external\NotFoundException;
 use \OCA\Files_External\Lib\Backend\Backend;
 use \OCA\Files_External\Lib\Auth\AuthMechanism;
+use OCP\Files\Config\IUserMountCache;
 use \OCP\Files\StorageNotAvailableException;
 
 /**
@@ -46,13 +47,20 @@ abstract class StoragesService {
 	 */
 	protected $dbConfig;
 
+	/**
+	 * @var IUserMountCache
+	 */
+	protected $userMountCache;
+
 	/**
 	 * @param BackendService $backendService
 	 * @param DBConfigService $dbConfigService
+	 * @param IUserMountCache $userMountCache
 	 */
-	public function __construct(BackendService $backendService, DBConfigService $dbConfigService) {
+	public function __construct(BackendService $backendService, DBConfigService $dbConfigService, IUserMountCache $userMountCache) {
 		$this->backendService = $backendService;
 		$this->dbConfig = $dbConfigService;
+		$this->userMountCache = $userMountCache;
 	}
 
 	protected function readDBConfig() {
@@ -416,6 +424,15 @@ abstract class StoragesService {
 
 		$this->triggerChangeHooks($oldStorage, $updatedStorage);
 
+		if (($wasGlobal && !$isGlobal) || count($removedGroups) > 0) { // to expensive to properly handle these on the fly
+			$this->userMountCache->remoteStorageMounts($this->getStorageId($updatedStorage));
+		} else {
+			$storageId = $this->getStorageId($updatedStorage);
+			foreach ($removedUsers as $userId) {
+				$this->userMountCache->removeUserStorageMount($storageId, $userId);
+			}
+		}
+
 		return $this->getStorage($id);
 	}
 
@@ -480,4 +497,25 @@ abstract class StoragesService {
 		return $storageImpl->getId();
 	}
 
+	/**
+	 * Construct the storage implementation
+	 *
+	 * @param StorageConfig $storageConfig
+	 * @return int
+	 */
+	private function getStorageId(StorageConfig $storageConfig) {
+		try {
+			$class = $storageConfig->getBackend()->getStorageClass();
+			/** @var \OC\Files\Storage\Storage $storage */
+			$storage = new $class($storageConfig->getBackendOptions());
+
+			// auth mechanism should fire first
+			$storage = $storageConfig->getBackend()->wrapStorage($storage);
+			$storage = $storageConfig->getAuthMechanism()->wrapStorage($storage);
+
+			return $storage->getStorageCache()->getNumericId();
+		} catch (\Exception $e) {
+			return -1;
+		}
+	}
 }
diff --git a/apps/files_external/service/userglobalstoragesservice.php b/apps/files_external/service/userglobalstoragesservice.php
index 6407db2dd5..03c831fe97 100644
--- a/apps/files_external/service/userglobalstoragesservice.php
+++ b/apps/files_external/service/userglobalstoragesservice.php
@@ -25,6 +25,7 @@ namespace OCA\Files_External\Service;
 
 use \OCA\Files_external\Service\GlobalStoragesService;
 use \OCA\Files_External\Service\BackendService;
+use OCP\Files\Config\IUserMountCache;
 use \OCP\IUserSession;
 use \OCP\IGroupManager;
 use \OCA\Files_External\Service\UserTrait;
@@ -46,14 +47,16 @@ class UserGlobalStoragesService extends GlobalStoragesService {
 	 * @param DBConfigService $dbConfig
 	 * @param IUserSession $userSession
 	 * @param IGroupManager $groupManager
+	 * @param IUserMountCache $userMountCache
 	 */
 	public function __construct(
 		BackendService $backendService,
 		DBConfigService $dbConfig,
 		IUserSession $userSession,
-		IGroupManager $groupManager
+		IGroupManager $groupManager,
+		IUserMountCache $userMountCache
 	) {
-		parent::__construct($backendService, $dbConfig);
+		parent::__construct($backendService, $dbConfig, $userMountCache);
 		$this->userSession = $userSession;
 		$this->groupManager = $groupManager;
 	}
diff --git a/apps/files_external/service/userstoragesservice.php b/apps/files_external/service/userstoragesservice.php
index 2805d9e693..d4b04de609 100644
--- a/apps/files_external/service/userstoragesservice.php
+++ b/apps/files_external/service/userstoragesservice.php
@@ -23,6 +23,7 @@
 
 namespace OCA\Files_external\Service;
 
+use OCP\Files\Config\IUserMountCache;
 use \OCP\IUserSession;
 use \OC\Files\Filesystem;
 
@@ -44,14 +45,16 @@ class UserStoragesService extends StoragesService {
 	 * @param BackendService $backendService
 	 * @param DBConfigService $dbConfig
 	 * @param IUserSession $userSession user session
+	 * @param IUserMountCache $userMountCache
 	 */
 	public function __construct(
 		BackendService $backendService,
 		DBConfigService $dbConfig,
-		IUserSession $userSession
+		IUserSession $userSession,
+		IUserMountCache $userMountCache
 	) {
 		$this->userSession = $userSession;
-		parent::__construct($backendService, $dbConfig);
+		parent::__construct($backendService, $dbConfig, $userMountCache);
 	}
 
 	protected function readDBConfig() {
diff --git a/apps/files_external/tests/service/globalstoragesservicetest.php b/apps/files_external/tests/service/globalstoragesservicetest.php
index 7fc60efca0..6cdfbef82d 100644
--- a/apps/files_external/tests/service/globalstoragesservicetest.php
+++ b/apps/files_external/tests/service/globalstoragesservicetest.php
@@ -34,7 +34,7 @@ use \OCA\Files_external\Lib\StorageConfig;
 class GlobalStoragesServiceTest extends StoragesServiceTest {
 	public function setUp() {
 		parent::setUp();
-		$this->service = new GlobalStoragesService($this->backendService, $this->dbConfig);
+		$this->service = new GlobalStoragesService($this->backendService, $this->dbConfig, $this->mountCache);
 	}
 
 	public function tearDown() {
diff --git a/apps/files_external/tests/service/storagesservicetest.php b/apps/files_external/tests/service/storagesservicetest.php
index 710d804fd3..68671b599b 100644
--- a/apps/files_external/tests/service/storagesservicetest.php
+++ b/apps/files_external/tests/service/storagesservicetest.php
@@ -76,6 +76,11 @@ abstract class StoragesServiceTest extends \Test\TestCase {
 	 */
 	protected static $hookCalls;
 
+	/**
+	 * @var \PHPUnit_Framework_MockObject_MockObject|\OCP\Files\Config\IUserMountCache
+	 */
+	protected $mountCache;
+
 	public function setUp() {
 		parent::setUp();
 		$this->dbConfig = new CleaningDBConfig(\OC::$server->getDatabaseConnection());
@@ -87,6 +92,8 @@ abstract class StoragesServiceTest extends \Test\TestCase {
 		);
 		\OC_Mount_Config::$skipTest = true;
 
+		$this->mountCache = $this->getMock('OCP\Files\Config\IUserMountCache');
+
 		// prepare BackendService mock
 		$this->backendService =
 			$this->getMockBuilder('\OCA\Files_External\Service\BackendService')
diff --git a/apps/files_external/tests/service/userglobalstoragesservicetest.php b/apps/files_external/tests/service/userglobalstoragesservicetest.php
index a22e287407..baecf143c6 100644
--- a/apps/files_external/tests/service/userglobalstoragesservicetest.php
+++ b/apps/files_external/tests/service/userglobalstoragesservicetest.php
@@ -94,7 +94,8 @@ class UserGlobalStoragesServiceTest extends GlobalStoragesServiceTest {
 			$this->backendService,
 			$this->dbConfig,
 			$userSession,
-			$this->groupManager
+			$this->groupManager,
+			$this->mountCache
 		);
 	}
 
diff --git a/apps/files_external/tests/service/userstoragesservicetest.php b/apps/files_external/tests/service/userstoragesservicetest.php
index bf0efc13cf..37423cb8d7 100644
--- a/apps/files_external/tests/service/userstoragesservicetest.php
+++ b/apps/files_external/tests/service/userstoragesservicetest.php
@@ -49,7 +49,7 @@ class UserStoragesServiceTest extends StoragesServiceTest {
 	public function setUp() {
 		parent::setUp();
 
-		$this->globalStoragesService = new GlobalStoragesService($this->backendService, $this->dbConfig);
+		$this->globalStoragesService = new GlobalStoragesService($this->backendService, $this->dbConfig, $this->mountCache);
 
 		$this->userId = $this->getUniqueID('user_');
 		$this->createUser($this->userId, $this->userId);
@@ -62,7 +62,7 @@ class UserStoragesServiceTest extends StoragesServiceTest {
 			->method('getUser')
 			->will($this->returnValue($this->user));
 
-		$this->service = new UserStoragesService($this->backendService, $this->dbConfig, $userSession);
+		$this->service = new UserStoragesService($this->backendService, $this->dbConfig, $userSession, $this->mountCache);
 	}
 
 	private function makeTestStorageData() {
diff --git a/lib/private/files/config/usermountcache.php b/lib/private/files/config/usermountcache.php
index e60c6d0400..5fa192d105 100644
--- a/lib/private/files/config/usermountcache.php
+++ b/lib/private/files/config/usermountcache.php
@@ -230,4 +230,21 @@ class UserMountCache implements IUserMountCache {
 			->where($builder->expr()->eq('user_id', $builder->createNamedParameter($user->getUID())));
 		$query->execute();
 	}
+
+	public function removeUserStorageMount($storageId, $userId) {
+		$builder = $this->connection->getQueryBuilder();
+
+		$query = $builder->delete('mounts')
+			->where($builder->expr()->eq('user_id', $builder->createNamedParameter($userId)))
+			->andWhere($builder->expr()->eq('storage_id', $builder->createNamedParameter($storageId, \PDO::PARAM_INT)));
+		$query->execute();
+	}
+
+	public function remoteStorageMounts($storageId) {
+		$builder = $this->connection->getQueryBuilder();
+
+		$query = $builder->delete('mounts')
+			->where($builder->expr()->eq('storage_id', $builder->createNamedParameter($storageId, \PDO::PARAM_INT)));
+		$query->execute();
+	}
 }
diff --git a/lib/public/files/config/iusermountcache.php b/lib/public/files/config/iusermountcache.php
index 888e5d41e2..f722ad1631 100644
--- a/lib/public/files/config/iusermountcache.php
+++ b/lib/public/files/config/iusermountcache.php
@@ -67,4 +67,23 @@ interface IUserMountCache {
 	 * @since 9.0.0
 	 */
 	public function removeUserMounts(IUser $user);
+
+	/**
+	 * Remove all mounts for a user and storage
+	 *
+	 * @param $storageId
+	 * @param string $userId
+	 * @return mixed
+	 * @since 9.0.0
+	 */
+	public function removeUserStorageMount($storageId, $userId);
+
+	/**
+	 * Remove all cached mounts for a storage
+	 *
+	 * @param $storageId
+	 * @return mixed
+	 * @since 9.0.0
+	 */
+	public function remoteStorageMounts($storageId);
 }