diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index c2af460b77d..696ee885990 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -5325,7 +5325,7 @@ class assign {
 
         // Give each submission plugin a chance to process the locking.
         $plugins = $this->get_submission_plugins();
-        $submission = $this->get_user_submission($userid, false);
+        $submission = $this->get_user_submission($userid, true);
         foreach ($plugins as $plugin) {
             if ($plugin->is_enabled() && $plugin->is_visible()) {
                 $plugin->lock($submission);
@@ -5362,7 +5362,7 @@ class assign {
         }
         // Give each submission plugin a chance to process the unlocking.
         $plugins = $this->get_submission_plugins();
-        $submission = $this->get_user_submission($userid, false);
+        $submission = $this->get_user_submission($userid, true);
         foreach ($plugins as $plugin) {
             if ($plugin->is_enabled() && $plugin->is_visible()) {
                 $plugin->unlock($submission);