diff --git a/apps/files_external/lib/config.php b/apps/files_external/lib/config.php
index 9a8b95c14c9..43275d36c06 100755
--- a/apps/files_external/lib/config.php
+++ b/apps/files_external/lib/config.php
@@ -359,7 +359,8 @@ class OC_Mount_Config {
 			$jsonFile = OC_User::getHome(OCP\User::getUser()).'/mount.json';
 		} else {
 			$phpFile = OC::$SERVERROOT.'/config/mount.php';
-			$jsonFile = \OC_Config::getValue("mount_file", \OC::$SERVERROOT . "/data/mount.json");
+			$datadir = \OC_Config::getValue('datadirectory', \OC::$SERVERROOT . '/data/');
+			$jsonFile = \OC_Config::getValue('mount_file', $datadir . '/mount.json');
 		}
 		if (is_file($jsonFile)) {
 			$mountPoints = json_decode(file_get_contents($jsonFile), true);
@@ -385,7 +386,8 @@ class OC_Mount_Config {
 		if ($isPersonal) {
 			$file = OC_User::getHome(OCP\User::getUser()).'/mount.json';
 		} else {
-			$file = \OC_Config::getValue("mount_file", \OC::$SERVERROOT . "/data/mount.json");
+			$datadir = \OC_Config::getValue('datadirectory', \OC::$SERVERROOT . '/data/');
+			$file = \OC_Config::getValue('mount_file', $datadir . '/mount.json');
 		}
 		$content = json_encode($data);
 		@file_put_contents($file, $content);
diff --git a/lib/private/files/filesystem.php b/lib/private/files/filesystem.php
index 952f9f9febf..7f7b6f7f468 100644
--- a/lib/private/files/filesystem.php
+++ b/lib/private/files/filesystem.php
@@ -320,7 +320,8 @@ class Filesystem {
 		else {
 			self::mount('\OC\Files\Storage\Local', array('datadir' => $root), $user);
 		}
-		$mount_file = \OC_Config::getValue("mount_file", \OC::$SERVERROOT . "/data/mount.json");
+		$datadir = \OC_Config::getValue("datadirectory", \OC::$SERVERROOT . "/data");
+		$mount_file = \OC_Config::getValue("mount_file", $datadir . "/mount.json");
 
 		//move config file to it's new position
 		if (is_file(\OC::$SERVERROOT . '/config/mount.json')) {