diff --git a/lib/file/file_storage.php b/lib/file/file_storage.php
index bc243c357bf..03663e11d9e 100644
--- a/lib/file/file_storage.php
+++ b/lib/file/file_storage.php
@@ -462,7 +462,7 @@ class file_storage {
 
         $file_record->filename = clean_param($file_record->filename, PARAM_FILE);
         if ($file_record->filename === '') {
-            // path must start and end with '/'
+            // filename must not be empty
             throw new file_exception('storedfileproblem', 'Invalid file name');
         }