diff --git a/system/src/Grav/Common/Themes.php b/system/src/Grav/Common/Themes.php
index 7df197807..ae2962ea9 100644
--- a/system/src/Grav/Common/Themes.php
+++ b/system/src/Grav/Common/Themes.php
@@ -13,6 +13,7 @@ use Grav\Common\Config\Config;
 use Grav\Common\File\CompiledYamlFile;
 use Grav\Common\Data\Blueprints;
 use Grav\Common\Data\Data;
+use Grav\Framework\Psr7\Response;
 use RocketTheme\Toolbox\Event\EventDispatcher;
 use RocketTheme\Toolbox\Event\EventSubscriberInterface;
 use RocketTheme\Toolbox\ResourceLocator\UniformResourceLocator;
@@ -214,7 +215,9 @@ class Themes extends Iterator
                 }
             }
         } elseif (!$locator('theme://') && !defined('GRAV_CLI')) {
-            exit("Theme '$name' does not exist, unable to display page.");
+            $response = new Response(500, [], "Theme '$name' does not exist, unable to display page.");
+
+            $grav->exit($response);
         }
 
         $this->config->set('theme', $config->get('themes.' . $name));
diff --git a/system/src/Grav/Common/Twig/TwigExtension.php b/system/src/Grav/Common/Twig/TwigExtension.php
index a0f53f5ee..166844c4a 100644
--- a/system/src/Grav/Common/Twig/TwigExtension.php
+++ b/system/src/Grav/Common/Twig/TwigExtension.php
@@ -29,6 +29,7 @@ use Grav\Common\User\Interfaces\UserInterface;
 use Grav\Common\Utils;
 use Grav\Common\Yaml;
 use Grav\Common\Helpers\Base32;
+use Grav\Framework\Psr7\Response;
 use RocketTheme\Toolbox\ResourceLocator\UniformResourceLocator;
 use Twig\Environment;
 use Twig\Extension\AbstractExtension;
@@ -1110,8 +1111,9 @@ class TwigExtension extends AbstractExtension implements GlobalsInterface
      */
     public function redirectFunc($url, $statusCode = 303)
     {
-        header('Location: ' . $url, true, $statusCode);
-        exit();
+        $response = new Response($statusCode, ['location' => $url]);
+
+        $this->grav->exit($response);
     }
 
     /**