diff --git a/lib/authlib.php b/lib/authlib.php
index 33a193f..cfb6cd8 100644
--- a/lib/authlib.php
+++ b/lib/authlib.php
@@ -1038,7 +1038,9 @@
     // Initialize alternate name fields to empty strings.
     $namefields = array_diff(get_all_user_name_fields(), useredit_get_required_name_fields());
     foreach ($namefields as $namefield) {
-        $user->$namefield = '';
+        if (!property_exists($user, $namefield)) {
+            $user->$namefield = '';
+        }
     }
     return $user;
 }