diff --git a/core/modules/book/src/BookManager.php b/core/modules/book/src/BookManager.php
index 3e14c40..eb5b582 100644
--- a/core/modules/book/src/BookManager.php
+++ b/core/modules/book/src/BookManager.php
@@ -249,6 +249,13 @@ public function updateOutline(NodeInterface $node) {
       return FALSE;
     }
 
+    // Prevent changes to the book outline if the node being saved is not the
+    // default revision.
+    if (!$node->isDefaultRevision()) {
+      drupal_set_message($this->t('You can only change the book outline for the published version of this content.'), 'error');
+      return FALSE;
+    }
+
     if (!empty($node->book['bid'])) {
       if ($node->book['bid'] == 'new') {
         // New nodes that are their own book.
diff --git a/core/modules/book/tests/src/Functional/BookContentModerationTest.php b/core/modules/book/tests/src/Functional/BookContentModerationTest.php
new file mode 100644
index 0000000..0b9c831
--- /dev/null
+++ b/core/modules/book/tests/src/Functional/BookContentModerationTest.php
@@ -0,0 +1,83 @@
+<?php
+
+namespace Drupal\Tests\book\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+use Drupal\workflows\Entity\Workflow;
+
+/**
+ * Tests Book and Content Moderation integration.
+ *
+ * @group book
+ */
+class BookContentModerationTest extends BrowserTestBase {
+
+  use BookTestTrait;
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = ['book', 'block', 'book_test', 'content_moderation'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+    $this->drupalPlaceBlock('page_title_block');
+
+    $workflow = Workflow::load('editorial');
+    $workflow->getTypePlugin()->addEntityTypeAndBundle('node', 'book');
+    $workflow->save();
+
+    // We need a user with additional content moderation permissions.
+    $this->bookAuthor = $this->drupalCreateUser(['create new books', 'create book content', 'edit own book content', 'add content to books', 'access printer-friendly version', 'view any unpublished content', 'use editorial transition create_new_draft', 'use editorial transition publish']);
+  }
+
+  /**
+   * Tests that book drafts can not modify the book outline.
+   */
+  public function testBookWithForwardRevisions() {
+    // Create two books.
+    $book_1_nodes = $this->createBook(t('Save and Publish'));
+    $book_1 = $this->book;
+
+    $this->createBook(t('Save and Publish'));
+    $book_2 = $this->book;
+
+    $this->drupalLogin($this->bookAuthor);
+
+    // Check that book pages display along with the correct outlines.
+    $this->book = $book_1;
+    $this->checkBookNode($book_1, [$book_1_nodes[0], $book_1_nodes[3], $book_1_nodes[4]], FALSE, FALSE, $book_1_nodes[0], []);
+    $this->checkBookNode($book_1_nodes[0], [$book_1_nodes[1], $book_1_nodes[2]], $book_1, $book_1, $book_1_nodes[1], [$book_1]);
+
+    // Try to move Node 2 to a different parent.
+    $edit['book[pid]'] = $book_1_nodes[3]->id();
+    $this->drupalPostForm('node/' . $book_1_nodes[1]->id() . '/edit', $edit, t('Save and Create New Draft'));
+
+    $this->assertSession()->pageTextContains('You can only change the book outline for the published version of this content.');
+
+    // Check that the book outline did not change.
+    $this->book = $book_1;
+    $this->checkBookNode($book_1, [$book_1_nodes[0], $book_1_nodes[3], $book_1_nodes[4]], FALSE, FALSE, $book_1_nodes[0], []);
+    $this->checkBookNode($book_1_nodes[0], [$book_1_nodes[1], $book_1_nodes[2]], $book_1, $book_1, $book_1_nodes[1], [$book_1]);
+
+    // Try to move Node 2 to a different book.
+    $edit['book[bid]'] = $book_2->id();
+    $this->drupalPostForm('node/' . $book_1_nodes[1]->id() . '/edit', $edit, t('Save and Create New Draft'));
+
+    $this->assertSession()->pageTextContains('You can only change the book outline for the published version of this content.');
+
+    // Check that the book outline did not change.
+    $this->book = $book_1;
+    $this->checkBookNode($book_1, [$book_1_nodes[0], $book_1_nodes[3], $book_1_nodes[4]], FALSE, FALSE, $book_1_nodes[0], []);
+    $this->checkBookNode($book_1_nodes[0], [$book_1_nodes[1], $book_1_nodes[2]], $book_1, $book_1, $book_1_nodes[1], [$book_1]);
+
+  }
+
+}
diff --git a/core/modules/book/tests/src/Functional/BookTest.php b/core/modules/book/tests/src/Functional/BookTest.php
index 66edec9..640859f 100644
--- a/core/modules/book/tests/src/Functional/BookTest.php
+++ b/core/modules/book/tests/src/Functional/BookTest.php
@@ -2,9 +2,7 @@
 
 namespace Drupal\Tests\book\Functional;
 
-use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Entity\EntityInterface;
 use Drupal\Tests\BrowserTestBase;
 use Drupal\user\RoleInterface;
 
@@ -15,6 +13,8 @@
  */
 class BookTest extends BrowserTestBase {
 
+  use BookTestTrait;
+
   /**
    * Modules to install.
    *
@@ -23,20 +23,6 @@ class BookTest extends BrowserTestBase {
   public static $modules = ['book', 'block', 'node_access_test', 'book_test'];
 
   /**
-   * A book node.
-   *
-   * @var \Drupal\node\NodeInterface
-   */
-  protected $book;
-
-  /**
-   * A user with permission to create and edit books.
-   *
-   * @var object
-   */
-  protected $bookAuthor;
-
-  /**
    * A user with permission to view a book and access printer-friendly version.
    *
    * @var object
@@ -76,39 +62,6 @@ protected function setUp() {
   }
 
   /**
-   * Creates a new book with a page hierarchy.
-   *
-   * @return \Drupal\node\NodeInterface[]
-   */
-  public function createBook() {
-    // Create new book.
-    $this->drupalLogin($this->bookAuthor);
-
-    $this->book = $this->createBookNode('new');
-    $book = $this->book;
-
-    /*
-     * Add page hierarchy to book.
-     * Book
-     *  |- Node 0
-     *   |- Node 1
-     *   |- Node 2
-     *  |- Node 3
-     *  |- Node 4
-     */
-    $nodes = [];
-    $nodes[] = $this->createBookNode($book->id()); // Node 0.
-    $nodes[] = $this->createBookNode($book->id(), $nodes[0]->book['nid']); // Node 1.
-    $nodes[] = $this->createBookNode($book->id(), $nodes[0]->book['nid']); // Node 2.
-    $nodes[] = $this->createBookNode($book->id()); // Node 3.
-    $nodes[] = $this->createBookNode($book->id()); // Node 4.
-
-    $this->drupalLogout();
-
-    return $nodes;
-  }
-
-  /**
    * Tests the book navigation cache context.
    *
    * @see \Drupal\book\Cache\BookNavigationCacheContext
@@ -230,147 +183,6 @@ public function testBook() {
   }
 
   /**
-   * Checks the outline of sub-pages; previous, up, and next.
-   *
-   * Also checks the printer friendly version of the outline.
-   *
-   * @param \Drupal\Core\Entity\EntityInterface $node
-   *   Node to check.
-   * @param $nodes
-   *   Nodes that should be in outline.
-   * @param $previous
-   *   (optional) Previous link node. Defaults to FALSE.
-   * @param $up
-   *   (optional) Up link node. Defaults to FALSE.
-   * @param $next
-   *   (optional) Next link node. Defaults to FALSE.
-   * @param array $breadcrumb
-   *   The nodes that should be displayed in the breadcrumb.
-   */
-  public function checkBookNode(EntityInterface $node, $nodes, $previous = FALSE, $up = FALSE, $next = FALSE, array $breadcrumb) {
-    // $number does not use drupal_static as it should not be reset
-    // since it uniquely identifies each call to checkBookNode().
-    static $number = 0;
-    $this->drupalGet('node/' . $node->id());
-
-    // Check outline structure.
-    if ($nodes !== NULL) {
-      $this->assertPattern($this->generateOutlinePattern($nodes), format_string('Node @number outline confirmed.', ['@number' => $number]));
-    }
-    else {
-      $this->pass(format_string('Node %number does not have outline.', ['%number' => $number]));
-    }
-
-    // Check previous, up, and next links.
-    if ($previous) {
-      /** @var \Drupal\Core\Url $url */
-      $url = $previous->urlInfo();
-      $url->setOptions(['attributes' => ['rel' => ['prev'], 'title' => t('Go to previous page')]]);
-      $text = SafeMarkup::format('<b>‹</b> @label', ['@label' => $previous->label()]);
-      $this->assertRaw(\Drupal::l($text, $url), 'Previous page link found.');
-    }
-
-    if ($up) {
-      /** @var \Drupal\Core\Url $url */
-      $url = $up->urlInfo();
-      $url->setOptions(['attributes' => ['title' => t('Go to parent page')]]);
-      $this->assertRaw(\Drupal::l('Up', $url), 'Up page link found.');
-    }
-
-    if ($next) {
-      /** @var \Drupal\Core\Url $url */
-      $url = $next->urlInfo();
-      $url->setOptions(['attributes' => ['rel' => ['next'], 'title' => t('Go to next page')]]);
-      $text = SafeMarkup::format('@label <b>›</b>', ['@label' => $next->label()]);
-      $this->assertRaw(\Drupal::l($text, $url), 'Next page link found.');
-    }
-
-    // Compute the expected breadcrumb.
-    $expected_breadcrumb = [];
-    $expected_breadcrumb[] = \Drupal::url('<front>');
-    foreach ($breadcrumb as $a_node) {
-      $expected_breadcrumb[] = $a_node->url();
-    }
-
-    // Fetch links in the current breadcrumb.
-    $links = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
-    $got_breadcrumb = [];
-    foreach ($links as $link) {
-      $got_breadcrumb[] = $link->getAttribute('href');
-    }
-
-    // Compare expected and got breadcrumbs.
-    $this->assertIdentical($expected_breadcrumb, $got_breadcrumb, 'The breadcrumb is correctly displayed on the page.');
-
-    // Check printer friendly version.
-    $this->drupalGet('book/export/html/' . $node->id());
-    $this->assertText($node->label(), 'Printer friendly title found.');
-    $this->assertRaw($node->body->processed, 'Printer friendly body found.');
-
-    $number++;
-  }
-
-  /**
-   * Creates a regular expression to check for the sub-nodes in the outline.
-   *
-   * @param array $nodes
-   *   An array of nodes to check in outline.
-   *
-   * @return string
-   *   A regular expression that locates sub-nodes of the outline.
-   */
-  public function generateOutlinePattern($nodes) {
-    $outline = '';
-    foreach ($nodes as $node) {
-      $outline .= '(node\/' . $node->id() . ')(.*?)(' . $node->label() . ')(.*?)';
-    }
-
-    return '/<nav id="book-navigation-' . $this->book->id() . '"(.*?)<ul(.*?)' . $outline . '<\/ul>/s';
-  }
-
-  /**
-   * Creates a book node.
-   *
-   * @param int|string $book_nid
-   *   A book node ID or set to 'new' to create a new book.
-   * @param int|null $parent
-   *   (optional) Parent book reference ID. Defaults to NULL.
-   *
-   * @return \Drupal\node\NodeInterface
-   *   The created node.
-   */
-  public function createBookNode($book_nid, $parent = NULL) {
-    // $number does not use drupal_static as it should not be reset
-    // since it uniquely identifies each call to createBookNode().
-    static $number = 0; // Used to ensure that when sorted nodes stay in same order.
-
-    $edit = [];
-    $edit['title[0][value]'] = str_pad($number, 2, '0', STR_PAD_LEFT) . ' - SimpleTest test node ' . $this->randomMachineName(10);
-    $edit['body[0][value]'] = 'SimpleTest test body ' . $this->randomMachineName(32) . ' ' . $this->randomMachineName(32);
-    $edit['book[bid]'] = $book_nid;
-
-    if ($parent !== NULL) {
-      $this->drupalPostForm('node/add/book', $edit, t('Change book (update list of parents)'));
-
-      $edit['book[pid]'] = $parent;
-      $this->drupalPostForm(NULL, $edit, t('Save'));
-      // Make sure the parent was flagged as having children.
-      $parent_node = \Drupal::entityManager()->getStorage('node')->loadUnchanged($parent);
-      $this->assertFalse(empty($parent_node->book['has_children']), 'Parent node is marked as having children');
-    }
-    else {
-      $this->drupalPostForm('node/add/book', $edit, t('Save'));
-    }
-
-    // Check to make sure the book node was created.
-    $node = $this->drupalGetNodeByTitle($edit['title[0][value]']);
-    $this->assertNotNull(($node === FALSE ? NULL : $node), 'Book node found in database.');
-    $number++;
-
-    return $node;
-  }
-
-  /**
    * Tests book export ("printer-friendly version") functionality.
    */
   public function testBookExport() {
diff --git a/core/modules/book/tests/src/Functional/BookTestTrait.php b/core/modules/book/tests/src/Functional/BookTestTrait.php
new file mode 100644
index 0000000..87bbb8b
--- /dev/null
+++ b/core/modules/book/tests/src/Functional/BookTestTrait.php
@@ -0,0 +1,210 @@
+<?php
+
+namespace Drupal\Tests\book\Functional;
+
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\Entity\EntityInterface;
+
+/**
+ * Provides common functionality for Book test classes.
+ */
+trait BookTestTrait {
+
+  /**
+   * A book node.
+   *
+   * @var \Drupal\node\NodeInterface
+   */
+  protected $book;
+
+  /**
+   * A user with permission to create and edit books.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $bookAuthor;
+
+  /**
+   * Creates a new book with a page hierarchy.
+   *
+   * @param string $submit
+   *   (optional) Value of the submit button whose click is to be emulated.
+   *   Defaults to 'Save'.
+   *
+   * @return \Drupal\node\NodeInterface[]
+   */
+  public function createBook($submit = NULL) {
+    // Create new book.
+    $this->drupalLogin($this->bookAuthor);
+
+    $this->book = $this->createBookNode('new', NULL, $submit);
+    $book = $this->book;
+
+    /*
+     * Add page hierarchy to book.
+     * Book
+     *  |- Node 0
+     *   |- Node 1
+     *   |- Node 2
+     *  |- Node 3
+     *  |- Node 4
+     */
+    $nodes = [];
+    $nodes[] = $this->createBookNode($book->id(), NULL, $submit); // Node 0.
+    $nodes[] = $this->createBookNode($book->id(), $nodes[0]->book['nid'], $submit); // Node 1.
+    $nodes[] = $this->createBookNode($book->id(), $nodes[0]->book['nid'], $submit); // Node 2.
+    $nodes[] = $this->createBookNode($book->id(), NULL, $submit); // Node 3.
+    $nodes[] = $this->createBookNode($book->id(), NULL, $submit); // Node 4.
+
+    $this->drupalLogout();
+
+    return $nodes;
+  }
+
+  /**
+   * Checks the outline of sub-pages; previous, up, and next.
+   *
+   * Also checks the printer friendly version of the outline.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $node
+   *   Node to check.
+   * @param $nodes
+   *   Nodes that should be in outline.
+   * @param $previous
+   *   (optional) Previous link node. Defaults to FALSE.
+   * @param $up
+   *   (optional) Up link node. Defaults to FALSE.
+   * @param $next
+   *   (optional) Next link node. Defaults to FALSE.
+   * @param array $breadcrumb
+   *   The nodes that should be displayed in the breadcrumb.
+   */
+  public function checkBookNode(EntityInterface $node, $nodes, $previous = FALSE, $up = FALSE, $next = FALSE, array $breadcrumb) {
+    // $number does not use drupal_static as it should not be reset
+    // since it uniquely identifies each call to checkBookNode().
+    static $number = 0;
+    $this->drupalGet('node/' . $node->id());
+
+    // Check outline structure.
+    if ($nodes !== NULL) {
+      $this->assertPattern($this->generateOutlinePattern($nodes), format_string('Node @number outline confirmed.', ['@number' => $number]));
+    }
+    else {
+      $this->pass(format_string('Node %number does not have outline.', ['%number' => $number]));
+    }
+
+    // Check previous, up, and next links.
+    if ($previous) {
+      /** @var \Drupal\Core\Url $url */
+      $url = $previous->urlInfo();
+      $url->setOptions(['attributes' => ['rel' => ['prev'], 'title' => t('Go to previous page')]]);
+      $text = SafeMarkup::format('<b>‹</b> @label', ['@label' => $previous->label()]);
+      $this->assertRaw(\Drupal::l($text, $url), 'Previous page link found.');
+    }
+
+    if ($up) {
+      /** @var \Drupal\Core\Url $url */
+      $url = $up->urlInfo();
+      $url->setOptions(['attributes' => ['title' => t('Go to parent page')]]);
+      $this->assertRaw(\Drupal::l('Up', $url), 'Up page link found.');
+    }
+
+    if ($next) {
+      /** @var \Drupal\Core\Url $url */
+      $url = $next->urlInfo();
+      $url->setOptions(['attributes' => ['rel' => ['next'], 'title' => t('Go to next page')]]);
+      $text = SafeMarkup::format('@label <b>›</b>', ['@label' => $next->label()]);
+      $this->assertRaw(\Drupal::l($text, $url), 'Next page link found.');
+    }
+
+    // Compute the expected breadcrumb.
+    $expected_breadcrumb = [];
+    $expected_breadcrumb[] = \Drupal::url('<front>');
+    foreach ($breadcrumb as $a_node) {
+      $expected_breadcrumb[] = $a_node->url();
+    }
+
+    // Fetch links in the current breadcrumb.
+    $links = $this->xpath('//nav[@class="breadcrumb"]/ol/li/a');
+    $got_breadcrumb = [];
+    foreach ($links as $link) {
+      $got_breadcrumb[] = $link->getAttribute('href');
+    }
+
+    // Compare expected and got breadcrumbs.
+    $this->assertIdentical($expected_breadcrumb, $got_breadcrumb, 'The breadcrumb is correctly displayed on the page.');
+
+    // Check printer friendly version.
+    $this->drupalGet('book/export/html/' . $node->id());
+    $this->assertText($node->label(), 'Printer friendly title found.');
+    $this->assertRaw($node->body->processed, 'Printer friendly body found.');
+
+    $number++;
+  }
+
+  /**
+   * Creates a regular expression to check for the sub-nodes in the outline.
+   *
+   * @param array $nodes
+   *   An array of nodes to check in outline.
+   *
+   * @return string
+   *   A regular expression that locates sub-nodes of the outline.
+   */
+  public function generateOutlinePattern($nodes) {
+    $outline = '';
+    foreach ($nodes as $node) {
+      $outline .= '(node\/' . $node->id() . ')(.*?)(' . $node->label() . ')(.*?)';
+    }
+
+    return '/<nav id="book-navigation-' . $this->book->id() . '"(.*?)<ul(.*?)' . $outline . '<\/ul>/s';
+  }
+
+  /**
+   * Creates a book node.
+   *
+   * @param int|string $book_nid
+   *   A book node ID or set to 'new' to create a new book.
+   * @param int|null $parent
+   *   (optional) Parent book reference ID. Defaults to NULL.
+   * @param string $submit
+   *   (optional) Value of the submit button whose click is to be emulated.
+   *   Defaults to 'Save'.
+   *
+   * @return \Drupal\node\NodeInterface
+   *   The created node.
+   */
+  public function createBookNode($book_nid, $parent = NULL, $submit = NULL) {
+    // $number does not use drupal_static as it should not be reset
+    // since it uniquely identifies each call to createBookNode().
+    static $number = 0; // Used to ensure that when sorted nodes stay in same order.
+
+    $submit = $submit ?: t('Save');
+
+    $edit = [];
+    $edit['title[0][value]'] = str_pad($number, 2, '0', STR_PAD_LEFT) . ' - SimpleTest test node ' . $this->randomMachineName(10);
+    $edit['body[0][value]'] = 'SimpleTest test body ' . $this->randomMachineName(32) . ' ' . $this->randomMachineName(32);
+    $edit['book[bid]'] = $book_nid;
+
+    if ($parent !== NULL) {
+      $this->drupalPostForm('node/add/book', $edit, t('Change book (update list of parents)'));
+
+      $edit['book[pid]'] = $parent;
+      $this->drupalPostForm(NULL, $edit, $submit);
+      // Make sure the parent was flagged as having children.
+      $parent_node = \Drupal::entityManager()->getStorage('node')->loadUnchanged($parent);
+      $this->assertFalse(empty($parent_node->book['has_children']), 'Parent node is marked as having children');
+    }
+    else {
+      $this->drupalPostForm('node/add/book', $edit, $submit);
+    }
+
+    // Check to make sure the book node was created.
+    $node = $this->drupalGetNodeByTitle($edit['title[0][value]']);
+    $this->assertNotNull(($node === FALSE ? NULL : $node), 'Book node found in database.');
+    $number++;
+
+    return $node;
+  }
+
+}
diff --git a/core/modules/book/tests/src/Kernel/BookForwardRevisionTest.php b/core/modules/book/tests/src/Kernel/BookForwardRevisionTest.php
new file mode 100644
index 0000000..466f96c
--- /dev/null
+++ b/core/modules/book/tests/src/Kernel/BookForwardRevisionTest.php
@@ -0,0 +1,79 @@
+<?php
+
+namespace Drupal\Tests\book\Kernel;
+
+use Drupal\node\Entity\Node;
+use Drupal\node\Entity\NodeType;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests that the Book module handles forward revisions correctly.
+ *
+ * @group book
+ */
+class BookForwardRevisionTest extends KernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['system', 'user', 'field', 'filter', 'text', 'node', 'book'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->installEntitySchema('user');
+    $this->installEntitySchema('node');
+    $this->installSchema('book', ['book']);
+    $this->installSchema('node', ['node_access']);
+    $this->installConfig(['node', 'book', 'field']);
+  }
+
+  /**
+   * Tests forward revision handling for books.
+   */
+  public function testBookWithForwardRevisions() {
+    $content_type = NodeType::create([
+      'type' => $this->randomMachineName(),
+      'name' => $this->randomString(),
+    ]);
+    $content_type->save();
+    $book_config = $this->config('book.settings');
+    $allowed_types = $book_config->get('allowed_types');
+    $allowed_types[] = $content_type->id();
+    $book_config->set('allowed_types', $allowed_types)->save();
+
+    // Create two top-level books a child.
+    $book_1 = Node::create(['title' => $this->randomString(), 'type' => $content_type->id()]);
+    $book_1->book['bid'] = 'new';
+    $book_1->save();
+
+    $book_2 = Node::create(['title' => $this->randomString(), 'type' => $content_type->id()]);
+    $book_2->book['bid'] = 'new';
+    $book_2->save();
+
+    $child = Node::create(['title' => $this->randomString(), 'type' => $content_type->id()]);
+    $child->book['bid'] = $book_1->id();
+    $child->book['pid'] = $book_1->id();
+    $child->save();
+
+    // Try to move the child to a different book while saving it as a forward
+    // revision.
+    /** @var \Drupal\book\BookManagerInterface $book_manager */
+    $book_manager = $this->container->get('book.manager');
+
+    // Check that the API doesn't allow us to change the book outline for
+    // forward revisions.
+    $child->book['bid'] = $book_2->id();
+    $child->setNewRevision(TRUE);
+    $child->isDefaultRevision(FALSE);
+
+    $return = $book_manager->updateOutline($child);
+    $this->assertFalse($return, 'A forward revision can not change the book outline.');
+  }
+
+}