diff --git a/course/classes/local/service/content_item_service.php b/course/classes/local/service/content_item_service.php
index a3cf2f4d1a2..f5e00ee47dd 100644
--- a/course/classes/local/service/content_item_service.php
+++ b/course/classes/local/service/content_item_service.php
@@ -224,11 +224,8 @@ class content_item_service {
         $exported = $ciexporter->export($PAGE->get_renderer('core'));
 
         // Sort by title for return.
-        usort($exported->content_items, function($a, $b) {
-            return strcmp($a->title, $b->title);
-        });
-
-        return $exported->content_items;
+        \core_collator::asort_objects_by_property($exported->content_items, 'title');
+        return array_values($exported->content_items);
     }
 
     /**
@@ -300,11 +297,9 @@ class content_item_service {
         $exported = $ciexporter->export($PAGE->get_renderer('course'));
 
         // Sort by title for return.
-        usort($exported->content_items, function($a, $b) {
-            return strcmp($a->title, $b->title);
-        });
+        \core_collator::asort_objects_by_property($exported->content_items, 'title');
 
-        return $exported->content_items;
+        return array_values($exported->content_items);
     }
 
     /**