diff --git a/core/Controller/TaskProcessingApiController.php b/core/Controller/TaskProcessingApiController.php
index da1f339beac61..26fc93a4cd3c0 100644
--- a/core/Controller/TaskProcessingApiController.php
+++ b/core/Controller/TaskProcessingApiController.php
@@ -351,6 +351,9 @@ private function getFileContentsInternal(Task $task, int $fileId): Http\DataDown
 		if (!in_array($fileId, $ids)) {
 			return new DataResponse(['message' => $this->l->t('Not found')], Http::STATUS_NOT_FOUND);
 		}
+		if ($task->getUserId() !== null) {
+			\OC_Util::setupFS($task->getUserId());
+		}
 		$node = $this->rootFolder->getFirstNodeById($fileId);
 		if ($node === null) {
 			$node = $this->rootFolder->getFirstNodeByIdInPath($fileId, '/' . $this->rootFolder->getAppDataDirectoryName() . '/');