diff --git a/course/dnduploadlib.php b/course/dnduploadlib.php
index d3be854817a..655ddd11e7f 100644
--- a/course/dnduploadlib.php
+++ b/course/dnduploadlib.php
@@ -495,6 +495,8 @@ class dndupload_ajax_processor {
             throw new moodle_exception('errornouploadrepo', 'moodle');
         }
         $repo = reset($repo); // Get the first (and only) upload repo.
+        // Pre-emptively purge the navigation cache so the upload repo can close the session.
+        navigation_cache::destroy_volatile_caches();
         $details = $repo->process_upload(null, $maxbytes, $types, '/', $draftitemid);
         if (empty($this->displayname)) {
             $this->displayname = $this->display_name_from_file($details['file']);
diff --git a/repository/upload/lib.php b/repository/upload/lib.php
index f42c054b3a5..510b7d49b53 100644
--- a/repository/upload/lib.php
+++ b/repository/upload/lib.php
@@ -82,6 +82,8 @@ class repository_upload extends repository {
             $license = null, $author = '', $overwriteexisting = false, $areamaxbytes = FILE_AREA_MAX_BYTES_UNLIMITED) {
         global $USER, $CFG;
 
+        \core\session\manager::write_close();
+
         if ((is_array($types) and in_array('*', $types)) or $types == '*') {
             $this->mimetypes = '*';
         } else {