diff --git a/lib/form/templatable_form_element.php b/lib/form/templatable_form_element.php
index 447a822c918..870897da6f9 100644
--- a/lib/form/templatable_form_element.php
+++ b/lib/form/templatable_form_element.php
@@ -82,7 +82,8 @@ trait templatable_form_element {
         $context['type'] = $this->getType();
         $context['attributes'] = implode(' ', $otherattributes);
         $context['emptylabel'] = ($this->getLabel() === '');
-        $context['iderror'] = preg_replace('/^id_/', 'id_error_', $context['id']);
+        $context['iderror'] = preg_replace('/_id_/', '_id_error_', $context['id']);
+        $context['iderror'] = preg_replace('/^id_/', 'id_error_', $context['iderror']);
 
         // Elements with multiple values need array syntax.
         if ($this->getAttribute('multiple')) {