diff --git a/core/modules/book/book.module b/core/modules/book/book.module
index 7f7830c..93fa11f 100644
--- a/core/modules/book/book.module
+++ b/core/modules/book/book.module
@@ -319,11 +319,7 @@ function book_node_prepare_form(NodeInterface $node, $operation, FormStateInterf
     $node_ref = !$node->isNew() ? $node->id() : 'new';
     $node->book += $book_manager->getLinkDefaults($node_ref);
   }
-  else {
-    if (isset($node->book['bid']) && !isset($node->book['original_bid'])) {
-      $node->book['original_bid'] = $node->book['bid'];
-    }
-  }
+
   // Find the depth limit for the parent select.
   if (isset($node->book['bid']) && !isset($node->book['parent_depth_limit'])) {
     $node->book['parent_depth_limit'] = $book_manager->getParentDepthLimit($node->book);