diff --git a/core/modules/book/src/BookManager.php b/core/modules/book/src/BookManager.php
index b5c4f3b..4538658 100644
--- a/core/modules/book/src/BookManager.php
+++ b/core/modules/book/src/BookManager.php
@@ -251,7 +251,7 @@ public function updateOutline(NodeInterface $node) {
 
     // Prevent changes to the book outline if the node being saved is not the
     // default revision.
-    if ($node->isNewRevision() && !$node->isDefaultRevision()) {
+    if (!$node->isDefaultRevision()) {
       return FALSE;
     }