diff --git a/config/config.sample.php b/config/config.sample.php
index fc52edbc7785d17c7037b32ef71e374f92a5d81e..e95e99e229a762ff771d81a5309613cf6d53bf73 100644
--- a/config/config.sample.php
+++ b/config/config.sample.php
@@ -1005,9 +1005,9 @@ $CONFIG = array(
  *
  * One way to test is applying for a trystack account at http://trystack.org/
  */
-'objectstore' => array(
+'objectstore' => [
 	'class' => 'OC\\Files\\ObjectStore\\Swift',
-	'arguments' => array(
+	'arguments' => [
 		// trystack will user your facebook id as the user name
 		'username' => 'facebook100000123456789',
 		// in the trystack dashboard go to user -> settings -> API Password to
@@ -1015,6 +1015,8 @@ $CONFIG = array(
 		'password' => 'Secr3tPaSSWoRdt7',
 		// must already exist in the objectstore, name can be different
 		'container' => 'nextcloud',
+		// prefix to prepend to the fileid, default is 'oid:urn:'
+		'objectPrefix' => 'oid:urn:',
 		// create the container if it does not exist. default is false
 		'autocreate' => true,
 		// required, dev-/trystack defaults to 'RegionOne'
@@ -1028,8 +1030,8 @@ $CONFIG = array(
 		'serviceName' => 'swift',
 		// The Interface / url Type, optional
 		'urlType' => 'internal'
-	),
-),
+	],
+],
 
 
 /**
diff --git a/lib/private/Files/ObjectStore/ObjectStoreStorage.php b/lib/private/Files/ObjectStore/ObjectStoreStorage.php
index 0f0229c9ca5989432aa91fdf4311271360a58a79..2dcf830cc1e7f06d9bf1163c9b9685059ea3ee06 100644
--- a/lib/private/Files/ObjectStore/ObjectStoreStorage.php
+++ b/lib/private/Files/ObjectStore/ObjectStoreStorage.php
@@ -48,6 +48,8 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 	 */
 	protected $user;
 
+	private $objectPrefix = 'urn:oid:';
+
 	public function __construct($params) {
 		if (isset($params['objectstore']) && $params['objectstore'] instanceof IObjectStore) {
 			$this->objectStore = $params['objectstore'];
@@ -59,6 +61,9 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 		} else {
 			$this->id = 'object::store:' . $this->objectStore->getStorageId();
 		}
+		if (isset($params['objectPrefix'])) {
+			$this->objectPrefix = $params['objectPrefix'];
+		}
 		//initialize cache with root directory in cache
 		if (!$this->is_dir('/')) {
 			$this->mkdir('/');
@@ -216,7 +221,7 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 	 */
 	protected function getURN($fileId) {
 		if (is_numeric($fileId)) {
-			return 'urn:oid:' . $fileId;
+			return $this->objectPrefix . $fileId;
 		}
 		return null;
 	}
diff --git a/tests/objectstore/start-swift-ceph.sh b/tests/objectstore/start-swift-ceph.sh
index bbf483c28970b16df7e3dd9a48a7f5b9878d7db6..98c0e8b78b2f0e9dc7bf60f46ffdedbe19713c0d 100755
--- a/tests/objectstore/start-swift-ceph.sh
+++ b/tests/objectstore/start-swift-ceph.sh
@@ -85,6 +85,7 @@ cat > $thisFolder/swift.config.php <<DELIM
 		'username' => '$user',
 		'password' => '$pass',
 		'container' => 'owncloud-autotest$EXECUTOR_NUMBER',
+		'objectPrefix' => 'autotest$EXECUTOR_NUMBER:oid:urn:',
 		'autocreate' => true,
 		'region' => '$region',
 		'url' => 'http://$host:$port/v2.0',