diff --git a/src/Router/Route.php b/src/Router/Route.php
index be6054d..405f3a5 100644
--- a/src/Router/Route.php
+++ b/src/Router/Route.php
@@ -404,7 +404,7 @@ class Route
     public function isInContainedInValidDomains(): bool
     {
         foreach ($this->validDomains as $validDomain) {
-            if (fnmatch($validDomain, $_SERVER['HTTP_HOST'])) {
+            if (isset($_SERVER['HTTP_HOST']) && fnmatch($validDomain, $_SERVER['HTTP_HOST'])) {
                 return true;
             }
         }