diff --git a/core/lib/Drupal/Core/Form/FormBuilder.php b/core/lib/Drupal/Core/Form/FormBuilder.php
index 4fc013f..618bc98 100644
--- a/core/lib/Drupal/Core/Form/FormBuilder.php
+++ b/core/lib/Drupal/Core/Form/FormBuilder.php
@@ -735,7 +735,14 @@ protected function buildFormAction() {
     // @todo Remove this parsing once these are removed from the request in
     //   https://www.drupal.org/node/2504709.
     $parsed = UrlHelper::parse($request_uri);
-    unset($parsed['query'][static::AJAX_FORM_REQUEST], $parsed['query'][MainContentViewSubscriber::WRAPPER_FORMAT], $parsed['query']['destination']);
+    unset($parsed['query'][static::AJAX_FORM_REQUEST], $parsed['query'][MainContentViewSubscriber::WRAPPER_FORMAT]);
+
+    // Ignore the destination if the form is rendered inside a subrequest on a
+    // 403/404 page.
+    if ($request->query->has('_exception_statuscode') && $request->query->has('destination')) {
+      unset($parsed['query']['destination']);
+    }
+
     return $parsed['path'] . ($parsed['query'] ? ('?' . UrlHelper::buildQuery($parsed['query'])) : '');
   }