diff --git a/admin/tool/uploadcourse/classes/course.php b/admin/tool/uploadcourse/classes/course.php
index 629e498f82c..faa404d347f 100644
--- a/admin/tool/uploadcourse/classes/course.php
+++ b/admin/tool/uploadcourse/classes/course.php
@@ -715,6 +715,7 @@ class tool_uploadcourse_course {
                 $this->error('errorwhilerestoringcourse', new lang_string('errorwhilerestoringthecourse', 'tool_uploadcourse'));
             }
             $rc->destroy();
+            unset($rc); // File logging is a mess, we can only try to rely on gc to close handles.
         }
 
         // Proceed with enrolment data.
diff --git a/admin/tool/uploadcourse/classes/helper.php b/admin/tool/uploadcourse/classes/helper.php
index b328a423437..11ff373f5d7 100644
--- a/admin/tool/uploadcourse/classes/helper.php
+++ b/admin/tool/uploadcourse/classes/helper.php
@@ -44,6 +44,13 @@ class tool_uploadcourse_helper {
      */
     public static function clean_restore_content() {
         global $CFG;
+
+        // There are some sloppy unclosed file handles in backup/restore code,
+        // let's hope somebody unset all controllers before calling this
+        // and destroy magic will close all remaining open file handles,
+        // otherwise Windows will fail deleting the directory.
+        gc_collect_cycles();
+
         if (!empty($CFG->keeptempdirectoriesonbackup)) {
             $cache = cache::make('tool_uploadcourse', 'helper');
             $backupids = (array) $cache->get('backupids');
diff --git a/admin/tool/uploadcourse/tests/helper_test.php b/admin/tool/uploadcourse/tests/helper_test.php
index 873e2216130..31e53e04d61 100644
--- a/admin/tool/uploadcourse/tests/helper_test.php
+++ b/admin/tool/uploadcourse/tests/helper_test.php
@@ -129,6 +129,7 @@ class tool_uploadcourse_helper_testcase extends advanced_testcase {
         $this->assertTrue(isset($result['backup_destination']));
         $c1backupfile = $result['backup_destination']->copy_content_to_temp();
         $bc->destroy();
+        unset($bc); // File logging is a mess, we can only try to rely on gc to close handles.
 
         // Creating backup file.
         $bc = new backup_controller(backup::TYPE_1COURSE, $c2->id, backup::FORMAT_MOODLE,
@@ -138,6 +139,7 @@ class tool_uploadcourse_helper_testcase extends advanced_testcase {
         $this->assertTrue(isset($result['backup_destination']));
         $c2backupfile = $result['backup_destination']->copy_content_to_temp();
         $bc->destroy();
+        unset($bc); // File logging is a mess, we can only try to rely on gc to close handles.
 
         // Checking restore dir.
         $dir = tool_uploadcourse_helper::get_restore_content_dir($c1backupfile, null);