diff --git a/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php b/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php
index 2ec806a..f9517e4 100644
--- a/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php
+++ b/core/modules/menu_link_content/src/Form/MenuLinkContentForm.php
@@ -124,7 +124,10 @@ public function validateForm(array &$form, FormStateInterface $form_state) {
         if ($user_url) {
           // If the user entered the special case "<front>" we must allow this
           // to not correspond to what Drupal thinks the URL is.
-          $user_link = str_replace('<front>', '/', $user_link);
+          if ($user_link == '<front>') {
+            global $base_path;
+            $user_link = str_replace('<front>', $base_path, $user_link);
+          }
           // Compare the generated link from what Drupal thinks this is. We want
           // to do this without language prefixes, if applicable.
           $user_url->setOption('language', $this->language_manager->getDefaultLanguage());