diff --git a/apps/files_sharing/lib/External/Storage.php b/apps/files_sharing/lib/External/Storage.php
index 29b9c7b563..bc8d898f8e 100644
--- a/apps/files_sharing/lib/External/Storage.php
+++ b/apps/files_sharing/lib/External/Storage.php
@@ -32,6 +32,7 @@ use OC\Files\Storage\DAV;
 use OC\ForbiddenException;
 use OCA\FederatedFileSharing\DiscoveryManager;
 use OCA\Files_Sharing\ISharedStorage;
+use OCP\AppFramework\Http;
 use OCP\Files\NotFoundException;
 use OCP\Files\StorageInvalidException;
 use OCP\Files\StorageNotAvailableException;
@@ -181,6 +182,20 @@ class Storage extends DAV implements ISharedStorage {
 		}
 	}
 
+	public function test() {
+		try {
+			parent::test();
+		} catch (StorageInvalidException $e) {
+			// check if it needs to be removed
+			$this->checkStorageAvailability();
+			throw $e;
+		} catch (StorageNotAvailableException $e) {
+			// check if it needs to be removed or just temp unavailable
+			$this->checkStorageAvailability();
+			throw $e;
+		}
+	}
+
 	/**
 	 * Check whether this storage is permanently or temporarily
 	 * unavailable
@@ -310,10 +325,10 @@ class Storage extends DAV implements ISharedStorage {
 				'connect_timeout' => 10,
 			]);
 		} catch (\GuzzleHttp\Exception\RequestException $e) {
-			if ($e->getCode() === 401 || $e->getCode() === 403) {
+			if ($e->getCode() === Http::STATUS_UNAUTHORIZED || $e->getCode() === Http::STATUS_FORBIDDEN) {
 				throw new ForbiddenException();
 			}
-			if ($e->getCode() === 404) {
+			if ($e->getCode() === Http::STATUS_NOT_FOUND) {
 				throw new NotFoundException();
 			}
 			// throw this to be on the safe side: the share will still be visible
diff --git a/lib/private/Files/Storage/DAV.php b/lib/private/Files/Storage/DAV.php
index 0d41b3bab0..c8088a41c4 100644
--- a/lib/private/Files/Storage/DAV.php
+++ b/lib/private/Files/Storage/DAV.php
@@ -814,13 +814,13 @@ class DAV extends Common {
 	private function convertException(Exception $e, $path = '') {
 		Util::writeLog('files_external', $e->getMessage(), Util::ERROR);
 		if ($e instanceof ClientHttpException) {
-			if ($e->getHttpStatus() === 423) {
+			if ($e->getHttpStatus() === Http::STATUS_LOCKED) {
 				throw new \OCP\Lock\LockedException($path);
 			}
-			if ($e->getHttpStatus() === 401) {
+			if ($e->getHttpStatus() === Http::STATUS_UNAUTHORIZED) {
 				// either password was changed or was invalid all along
 				throw new StorageInvalidException(get_class($e) . ': ' . $e->getMessage());
-			} else if ($e->getHttpStatus() === 405) {
+			} else if ($e->getHttpStatus() === Http::STATUS_METHOD_NOT_ALLOWED) {
 				// ignore exception for MethodNotAllowed, false will be returned
 				return;
 			}