diff --git a/functions.inc.php b/functions.inc.php
index 5c16f068..6cf2bfb9 100644
--- a/functions.inc.php
+++ b/functions.inc.php
@@ -2392,7 +2392,7 @@ function getRemoteAddr()
  */
 function getSiteUrl(array $server = []): string
 {
-    if (Config::has('site_url')) {
+    if (is_string(Config::read('site_url'))) {
         $url = Config::read_string('site_url');
         if (!empty($url)) {
             return $url;