diff --git a/public/install.php b/public/install.php
index e9b0bf6aa5a7f2ba503404ee0db0ce24048fabd2..4e54575875b6454759f84a11752502871cf15c5c 100644
--- a/public/install.php
+++ b/public/install.php
@@ -43,7 +43,7 @@ if (!function_exists('_')) {
 } else {
     require_once 'lib/language.inc.php';
 
-    foreach (explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE']) as $lang) {
+    foreach (explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE'] ?? '') as $lang) {
         [$lang, ] = explode(';', $lang);
         $lang = substr($lang, 0, 2);