diff --git a/httprl.module b/httprl.module
index 0151e10..9b37388 100644
--- a/httprl.module
+++ b/httprl.module
@@ -2013,6 +2013,9 @@ function httprl_queue_background_callback(&$args, &$result = NULL) {
   if (isset($callback_options['options']) && is_array($callback_options['options'])) {
     $options += $callback_options['options'];
   }
+  if (empty($options['headers']['Host']) && !empty($_SERVER['HTTP_HOST'])) {
+    $options['headers']['Host'] = $_SERVER['HTTP_HOST'];
+  }
   // Send Request.
   return httprl_request($url, $options);
 }