diff --git a/includes/smarty.php b/includes/smarty.php
index 30d0ad6..8e89451 100644
--- a/includes/smarty.php
+++ b/includes/smarty.php
@@ -170,6 +170,9 @@ function fatal_error($error) {
   if (php_sapi_name() == "cli")
     die("FATAL ERROR : $error\n");
 
+  // Set HTTP reponse code to 500
+  http_response_code(500);
+
   if ($ajax)
     display_ajax_return(array('error' => $error));