diff --git a/actions/admin/settings/180.antispam.php b/actions/admin/settings/180.antispam.php
index b599a443..6a3c67b2 100644
--- a/actions/admin/settings/180.antispam.php
+++ b/actions/admin/settings/180.antispam.php
@@ -129,7 +129,7 @@ return [
 					'settinggroup' => 'spf',
 					'varname' => 'spf_entry',
 					'type' => 'text',
-					'string_regexp' => '/^v=spf[a-z0-9:~?\s.-]+$/i',
+					'string_regexp' => '/^v=spf[a-z0-9:~?\s.-\/]+$/i',
 					'default' => 'v=spf1 a mx -all',
 					'save_method' => 'storeSettingField'
 				],