diff -u b/core/modules/book/src/BookOutlineStorage.php b/core/modules/book/src/BookOutlineStorage.php
--- b/core/modules/book/src/BookOutlineStorage.php
+++ b/core/modules/book/src/BookOutlineStorage.php
@@ -45,10 +45,10 @@
       return $this->connection->query("SELECT DISTINCT(bid) FROM {book}")->fetchCol();
     }
     elseif ($this->currentUser->hasPermission('view own unpublished content')) {
-      return $this->connection->query("SELECT DISTINCT(bid) FROM {book} b INNER JOIN {node_field_data} f ON b.nid = f.nid WHERE f.uid = $currentUserId OR f.status = 1")->fetchCol();
+      return $this->connection->query("SELECT DISTINCT(bid) FROM {book} b INNER JOIN {node_field_data} f ON b.nid = f.nid WHERE b.pid = 0 AND (f.uid = $currentUserId OR f.status = 1)")->fetchCol();
     }
     else {
-      return $this->connection->query("SELECT DISTINCT(bid) FROM {book} b INNER JOIN {node_field_data} f ON b.nid = f.nid WHERE f.status = 1")->fetchCol();
+      return $this->connection->query("SELECT DISTINCT(bid) FROM {book} b INNER JOIN {node_field_data} f ON b.nid = f.nid WHERE f.status = 1 AND b.pid = 0")->fetchCol();
     }
   }