diff --git a/frontends/php/app/views/administration.authentication.edit.php b/frontends/php/app/views/administration.authentication.edit.php
index 821c809..253cbeb 100644
--- a/frontends/php/app/views/administration.authentication.edit.php
+++ b/frontends/php/app/views/administration.authentication.edit.php
@@ -133,6 +133,7 @@ $ldap_tab = (new CFormList('list_ldap'))
 			->setAriaRequired()
 );
 
+$tab_cookie = get_cookie('tab', 0);
 (new CWidget())
 	->setTitle(_('Authentication'))
 	->addItem((new CForm())
@@ -149,7 +150,7 @@ $ldap_tab = (new CFormList('list_ldap'))
 			->setFooter(makeFormFooter(
 				(new CSubmit('update', _('Update'))),
 				[(new CSubmitButton(_('Test'), 'ldap_test', 1))
-					->addStyle(($data['form_refresh'] && get_cookie('tab', 0) == 2) ? '' : 'display: none')
+					->addStyle(($data['form_refresh'] && $tab_cookie == 2) ? '' : 'display: none')
 					->setEnabled($data['ldap_enabled'])
 				]
 			))