diff --git a/core/includes/common.inc b/core/includes/common.inc
index 29f1ef1..3706049 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -699,18 +699,6 @@ function drupal_site_offline() {
 }
 
 /**
- * Delivers a "page not found" error to the browser.
- *
- * Page callback functions wanting to report a "page not found" message should
- * return MENU_NOT_FOUND instead of calling drupal_not_found(). However,
- * functions that are invoked in contexts where that return value might not
- * bubble up to menu_execute_active_handler() should call drupal_not_found().
- */
-function drupal_not_found() {
-  throw new NotFoundHttpException();
-}
-
-/**
  * Delivers an "access denied" error to the browser.
  *
  * Page callback functions wanting to report an "access denied" message should
@@ -2354,8 +2342,7 @@ function l($text, $path, array $options = array()) {
  * Delivers a page callback result to the browser in the appropriate format.
  *
  * This function is most commonly called by menu_execute_active_handler(), but
- * can also be called by error conditions such as drupal_not_found(),
- * drupal_access_denied(), and drupal_site_offline().
+ * can also be called by error conditions such as drupal_site_offline().
  *
  * When a user requests a page, index.php calls menu_execute_active_handler(),
  * which calls the 'page callback' function registered in hook_menu(). The page
diff --git a/core/includes/file.inc b/core/includes/file.inc
index f6cab86..3a0a68b 100644
--- a/core/includes/file.inc
+++ b/core/includes/file.inc
@@ -1997,7 +1997,7 @@ function file_transfer($uri, $headers) {
  * modules returned headers the download will start with the returned headers.
  * If a module returns -1 drupal_access_denied() will be returned. If the file
  * exists but no modules responded drupal_access_denied() will be returned.
- * If the file does not exist drupal_not_found() will be returned.
+ * If the file does not exist a NotFoundHttpException() will be thrown.
  *
  * @see hook_file_download()
  * @see system_menu()
diff --git a/core/modules/book/book.pages.inc b/core/modules/book/book.pages.inc
index aedde16..c00fb6f 100644
--- a/core/modules/book/book.pages.inc
+++ b/core/modules/book/book.pages.inc
@@ -6,6 +6,7 @@
  */
 
 use Drupal\node\Node;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
  * Page callback: Prints a listing of all books.
@@ -53,7 +54,7 @@ function book_export($type, $nid) {
   }
   else {
     drupal_set_message(t('Unknown export format.'));
-    drupal_not_found();
+    throw new NotFoundHttpException();
   }
 }
 
@@ -84,7 +85,7 @@ function book_export_html($nid) {
       return theme('book_export_html', array('title' => $node->title, 'contents' => $contents, 'depth' => $node->book['depth']));
     }
     else {
-      drupal_not_found();
+      throw new NotFoundHttpException();
     }
   }
   else {
diff --git a/core/modules/comment/comment.admin.inc b/core/modules/comment/comment.admin.inc
index 9eabe13..4329492 100644
--- a/core/modules/comment/comment.admin.inc
+++ b/core/modules/comment/comment.admin.inc
@@ -6,6 +6,7 @@
  */
 
 use Drupal\comment\Comment;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
  * Page callback: Presents an administrative comment listing.
@@ -260,7 +261,7 @@ function comment_confirm_delete_page($cid) {
   if ($comment = comment_load($cid)) {
     return drupal_get_form('comment_confirm_delete', $comment);
   }
-  drupal_not_found();
+  throw new NotFoundHttpException();
 }
 
 /**
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 58ea4a6..4fa8fee 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -10,6 +10,7 @@
  */
 
 use Drupal\node\Node;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
  * Comment is awaiting approval.
@@ -506,7 +507,7 @@ function comment_permalink($cid) {
     $_GET['page'] = $page;
     return menu_execute_active_handler('node/' . $node->nid, FALSE);
   }
-  drupal_not_found();
+  throw new NotFoundHttpException();
 }
 
 /**
diff --git a/core/modules/comment/comment.pages.inc b/core/modules/comment/comment.pages.inc
index 2986d13..39b8a24 100644
--- a/core/modules/comment/comment.pages.inc
+++ b/core/modules/comment/comment.pages.inc
@@ -6,6 +6,7 @@
  */
 
 use Drupal\node\Node;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
  * Form constructor for the comment reply form.
@@ -122,5 +123,5 @@ function comment_approve($cid) {
     drupal_set_message(t('Comment approved.'));
     drupal_goto('node/' . $comment->nid);
   }
-  drupal_not_found();
+  throw new NotFoundHttpException();
 }
diff --git a/core/modules/contact/contact.pages.inc b/core/modules/contact/contact.pages.inc
index bf096a7..a1c2926 100644
--- a/core/modules/contact/contact.pages.inc
+++ b/core/modules/contact/contact.pages.inc
@@ -5,6 +5,8 @@
  * Page callbacks for the Contact module.
  */
 
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
 /**
  * Form constructor for the site-wide contact form.
  *
@@ -41,8 +43,7 @@ function contact_site_form($form, &$form_state) {
       drupal_set_message(t('The contact form has not been configured. <a href="@add">Add one or more categories</a> to the form.', array('@add' => url('admin/structure/contact/add'))), 'error');
     }
     else {
-      drupal_not_found();
-      drupal_exit();
+      throw new NotFoundHttpException();
     }
   }
 
diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index c124b9e..8fe85be 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -5,6 +5,8 @@
  * Administration functions for language.module.
  */
 
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
 /**
  * User interface for the language overview screen.
  */
@@ -375,8 +377,7 @@ function language_admin_delete_form($form, &$form_state, $language) {
   $languages = language_list();
 
   if (!isset($languages[$langcode])) {
-    drupal_not_found();
-    drupal_exit();
+    throw new NotFoundHttpException();
   }
   else {
     $form['langcode'] = array('#type' => 'value', '#value' => $langcode);
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index 8f26052..3b2d2ab 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -5,6 +5,8 @@
  * Interface translation summary, editing and deletion user interfaces.
  */
 
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
 /**
  * String search screen.
  */
@@ -511,7 +513,7 @@ function locale_translate_delete_page($lid) {
     return drupal_get_form('locale_translate_delete_form', $source);
   }
   else {
-    return drupal_not_found();
+    throw new NotFoundHttpException();
   }
 }
 
diff --git a/core/modules/openid/tests/openid_test.module b/core/modules/openid/tests/openid_test.module
index 4481818..89f3ddf 100644
--- a/core/modules/openid/tests/openid_test.module
+++ b/core/modules/openid/tests/openid_test.module
@@ -22,6 +22,7 @@
 
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
  * Implements hook_menu().
@@ -98,7 +99,7 @@ function openid_test_yadis_xrds() {
     // that the XRI has been properly encoded. The "+" sign in the _xrd_r query
     // parameter is decoded to a space by PHP.
     if (arg(3) == 'xri' && (arg(4) != '@example*résumé;%25' || $_GET['_xrd_r'] != 'application/xrds xml')) {
-      drupal_not_found();
+      throw new NotFoundHttpException();
     }
     $output = '<?xml version="1.0" encoding="UTF-8"?>
       <xrds:XRDS xmlns:xrds="xri://$xrds" xmlns="xri://$xrd*($v*2.0)" xmlns:openid="http://openid.net/xmlns/1.0">
diff --git a/core/modules/search/search.module b/core/modules/search/search.module
index 1ad7a85..f567dae 100644
--- a/core/modules/search/search.module
+++ b/core/modules/search/search.module
@@ -1034,9 +1034,8 @@ function search_box($form, &$form_state, $form_id) {
  */
 function search_box_form_submit($form, &$form_state) {
   // The search form relies on control of the redirect destination for its
-  // functionality, so we override any static destination set in the request,
-  // for example by drupal_access_denied() or drupal_not_found()
-  // (see http://drupal.org/node/292565).
+  // functionality, so we override any static destination set in the request.
+  // See http://drupal.org/node/292565.
   if (isset($_GET['destination'])) {
     unset($_GET['destination']);
   }
diff --git a/core/modules/statistics/statistics.admin.inc b/core/modules/statistics/statistics.admin.inc
index 87ae6a5..3243b11 100644
--- a/core/modules/statistics/statistics.admin.inc
+++ b/core/modules/statistics/statistics.admin.inc
@@ -5,6 +5,8 @@
  * Admin page callbacks for the Statistics module.
  */
 
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
 /**
  * Page callback: Displays the "recent hits" page.
  *
@@ -225,7 +227,7 @@ function statistics_top_referrers() {
  *
  * @return array
  *   A render array containing page access statistics. If information for the
- *   page was not found, drupal_not_found() is called.
+ *   page was not found, NotFoundHttpException() is thrown.
  */
 function statistics_access_log($aid) {
   $access = db_query('SELECT a.*, u.name FROM {accesslog} a LEFT JOIN {users} u ON a.uid = u.uid WHERE aid = :aid', array(':aid' => $aid))->fetch();
@@ -264,7 +266,7 @@ function statistics_access_log($aid) {
     return $build;
   }
   else {
-    drupal_not_found();
+    throw new NotFoundHttpException();
   }
 }
 
diff --git a/core/modules/statistics/statistics.pages.inc b/core/modules/statistics/statistics.pages.inc
index 1b776d1..0a1d611 100644
--- a/core/modules/statistics/statistics.pages.inc
+++ b/core/modules/statistics/statistics.pages.inc
@@ -5,13 +5,15 @@
  * User page callbacks for the Statistics module.
  */
 
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
 /**
  * Page callback: Displays statistics for a node.
  *
  * @return array
  *   A render array containing node statistics. If information for the node was
- *   not found, this will deliver a page not found error via
- *   drupal_not_found().
+ *   not found, this will deliver a page not found error by throwing a
+ *   NotFoundHttpException().
  *
  * @see statistics_menu()
  */
@@ -58,7 +60,7 @@ function statistics_node_tracker() {
     return $build;
   }
   else {
-    drupal_not_found();
+    throw new NotFoundHttpException();
   }
 }
 
@@ -67,8 +69,8 @@ function statistics_node_tracker() {
  *
  * @return array
  *   A render array containing user statistics. If information for the user was
- *   not found, this will deliver a page not found error via
- *   drupal_not_found().
+ *   not found, this will deliver a page not found error by throwing a
+ *   NotFoundHttpException();
  *
  * @see statistics_menu()
  */
@@ -106,6 +108,6 @@ function statistics_user_tracker() {
     return $build;
   }
   else {
-    drupal_not_found();
+    throw new NotFoundHttpException();
   }
 }
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 09ef3f5..519500e 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -1,6 +1,7 @@
 <?php
 
 use Drupal\Core\Database\Query\SelectInterface;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 /**
  * @file
@@ -2333,7 +2334,7 @@ function user_view_page($account) {
   }
   // An administrator may try to view a non-existent account,
   // so we give them a 404 (versus a 403 for non-admins).
-  drupal_not_found();
+  throw new NotFoundHttpException();
 }
 
 /**