diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index 97d59e588bf..14dc5d592c4 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -728,7 +728,7 @@ class assign {
                 $fileareas = array();
                 $plugincomponent = $plugin->get_subtype() . '_' . $plugin->get_type();
                 $fileareas = $plugin->get_file_areas();
-                foreach ($fileareas as $filearea) {
+                foreach ($fileareas as $filearea => $notused) {
                     $fs->delete_area_files($this->context->id, $plugincomponent, $filearea);
                 }
 
@@ -743,7 +743,7 @@ class assign {
                 $fileareas = array();
                 $plugincomponent = $plugin->get_subtype() . '_' . $plugin->get_type();
                 $fileareas = $plugin->get_file_areas();
-                foreach ($fileareas as $filearea) {
+                foreach ($fileareas as $filearea => $notused) {
                     $fs->delete_area_files($this->context->id, $plugincomponent, $filearea);
                 }