diff -u b/core/modules/book/src/BookManager.php b/core/modules/book/src/BookManager.php
--- b/core/modules/book/src/BookManager.php
+++ b/core/modules/book/src/BookManager.php
@@ -576,7 +576,8 @@
       // Allow book-specific theme overrides.
       $element['attributes'] = new Attribute();
       $element['title'] = $data['link']['title'];
-      $element['url'] = 'entity:node/' . $data['link']['nid'];
+      $node = $this->entityManager->getStorage('node')->load($data['link']['nid']);
+      $element['url'] = $node->urlInfo();
       $element['localized_options'] = !empty($data['link']['localized_options']) ? $data['link']['localized_options'] : [];
       $element['localized_options']['set_active_class'] = TRUE;
       $element['below'] = $data['below'] ? $this->buildItems($data['below']) : [];
@@ -597,8 +598,7 @@
       // Allow book-specific theme overrides.
       $element['attributes'] = new Attribute();
       $element['title'] = $data['link']['title'];
-      $node = $this->entityTypeManager->getStorage('node')->load($data['link']['nid']);
-      $element['url'] = $node->toUrl();
+      $element['url'] = 'entity:node/' . $data['link']['nid'];
       $element['localized_options'] = !empty($data['link']['localized_options']) ? $data['link']['localized_options'] : [];
       $element['localized_options']['set_active_class'] = TRUE;
       $element['below'] = $data['below'] ? $this->buildItems($data['below']) : [];