diff --git a/main/auth/inscription.php b/main/auth/inscription.php
index 42aae77722..d3ce888b9c 100755
--- a/main/auth/inscription.php
+++ b/main/auth/inscription.php
@@ -328,7 +328,7 @@ if (api_get_setting('allow_terms_conditions') == 'true') {
 	}
 	if ($term_preview['type'] == 1) {
 		$form->addElement('checkbox', 'legal_accept', null, get_lang('IHaveReadAndAgree').'&nbsp;<a href="inscription.php?legal" target="_blank">'.get_lang('TermsAndConditions').'</a>');
-		$form->addRule('extra_legal_accept',  get_lang('ThisFieldIsRequired'), 'required');
+		$form->addRule('legal_accept',  get_lang('ThisFieldIsRequired'), 'required');
 	} else {
 		if (!empty($term_preview['content'])) {
 			$preview = LegalManager::show_last_condition($term_preview);