diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index 385ef48..a53fbfc 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -823,6 +823,7 @@ function menu_link_rebuild_defaults() {
         $link['customized'] = $existing_item->customized;
         $link['updated'] = $existing_item->updated;
         $menu_link = $menu_link_storage->createFromDefaultLink($link);
+        $menu_link->enforceIsNew(FALSE);
 
         // Convert the existing item to a typed object.
         /** @var \Drupal\menu_link\MenuLinkInterface $existing_item */
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityBase.php b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
index 992c728..456bc83 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
@@ -894,6 +894,7 @@ public function createDuplicate() {
     $duplicate = clone $this;
     $entity_type = $this->getEntityType();
     $duplicate->{$entity_type->getKey('id')}->value = NULL;
+    $duplicate->enforceIsNew();
 
     // Check if the entity type supports UUIDs and generate a new one if so.
     if ($entity_type->hasKey('uuid')) {
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php b/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
index 0c2bfe4..cf43ee6 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php
@@ -67,6 +67,7 @@ public function create(array $values = array()) {
       $bundle = $values[$this->bundleKey];
     }
     $entity = new $entity_class(array(), $this->entityTypeId, $bundle);
+    $entity->enforceIsNew();
 
     foreach ($entity as $name => $field) {
       if (isset($values[$name])) {
diff --git a/core/lib/Drupal/Core/Entity/EntityDatabaseStorage.php b/core/lib/Drupal/Core/Entity/EntityDatabaseStorage.php
index c25ff56..180dfef 100644
--- a/core/lib/Drupal/Core/Entity/EntityDatabaseStorage.php
+++ b/core/lib/Drupal/Core/Entity/EntityDatabaseStorage.php
@@ -238,6 +238,7 @@ public function create(array $values = array()) {
     $entity_class::preCreate($this, $values);
 
     $entity = new $entity_class($values, $this->entityTypeId);
+    $entity->enforceIsNew();
 
     // Assign a new UUID if there is none yet.
     if ($this->uuidKey && !isset($entity->{$this->uuidKey})) {
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index c3b4981..ccbc098 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -1282,6 +1282,7 @@ function comment_prepare_author(CommentInterface $comment) {
   $account = $comment->getOwner();
   if (empty($account->uid->value)) {
     $account = entity_create('user', array('uid' => 0, 'name' => $comment->getAuthorName(), 'homepage' => $comment->getHomepage()));
+    $account->enforceIsNew(FALSE);
   }
   return $account;
 }
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php
index 9e42126..cee670a 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldAttachOtherTest.php
@@ -230,6 +230,7 @@ function testFieldAttachCache() {
       'type' => $entity_type,
       'id' => $entity->id(),
     ));
+    $entity->enforceIsNew(FALSE);
     $entity->{$this->field_name_2} = $values;
     $entity->save();
     $this->assertFalse(\Drupal::cache('entity')->get($cid), 'Cached: no cache entry on update');
@@ -245,6 +246,7 @@ function testFieldAttachCache() {
       'type' => $entity_type,
       'id' => $entity->id(),
     ));
+    $entity->enforceIsNew(FALSE);
     $values = $this->_generateTestFieldValues($this->field_2->getCardinality());
     $entity->{$this->field_name_2} = $values;
     $entity->setNewRevision();
diff --git a/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php
index efb6ae8..36017b0 100644
--- a/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldAttachStorageTest.php
@@ -182,6 +182,7 @@ function testFieldAttachSaveEmptyData() {
     $this->createFieldWithInstance('', $entity_type);
 
     $entity_init = entity_create($entity_type, array('id' => 1));
+    $entity_init->enforceIsNew(FALSE);
 
     // Insert: Field is NULL.
     $entity = clone $entity_init;
diff --git a/core/modules/file/file.module b/core/modules/file/file.module
index 2543616..2aeaed2 100644
--- a/core/modules/file/file.module
+++ b/core/modules/file/file.module
@@ -179,6 +179,7 @@ function file_copy(File $source, $destination = NULL, $replace = FILE_EXISTS_REN
         $existing = reset($existing_files);
         $file->fid = $existing->id();
         $file->setFilename($existing->getFilename());
+        $file->enforceIsNew(FALSE);
       }
     }
     // If we are renaming around an existing file (rather than a directory),
@@ -527,6 +528,7 @@ function file_save_data($data, $destination = NULL, $replace = FILE_EXISTS_RENAM
         $existing = reset($existing_files);
         $file->fid = $existing->id();
         $file->setFilename($existing->getFilename());
+        $file->enforceIsNew(FALSE);
       }
     }
     // If we are renaming around an existing file (rather than a directory),
@@ -952,6 +954,7 @@ function file_save_upload($form_field_name, array &$form_state, $validators = ar
       if (count($existing_files)) {
         $existing = reset($existing_files);
         $file->fid = $existing->id();
+        $file->enforceIsNew(FALSE);
       }
     }
 
diff --git a/core/modules/file/lib/Drupal/file/Tests/FileManagedTestBase.php b/core/modules/file/lib/Drupal/file/Tests/FileManagedTestBase.php
index c777691..00f4cb7 100644
--- a/core/modules/file/lib/Drupal/file/Tests/FileManagedTestBase.php
+++ b/core/modules/file/lib/Drupal/file/Tests/FileManagedTestBase.php
@@ -165,7 +165,9 @@ function createFile($filepath = NULL, $contents = NULL, $scheme = NULL) {
     $file['fid'] = db_insert('file_managed')
       ->fields($file)
       ->execute();
-    return entity_create('file', $file);
+    $file_entity = entity_create('file', $file);
+    $file_entity->enforceIsNew(FALSE);
+    return $file_entity;
   }
 
   /**
diff --git a/core/modules/file/lib/Drupal/file/Tests/FileManagedUnitTestBase.php b/core/modules/file/lib/Drupal/file/Tests/FileManagedUnitTestBase.php
index c9ec86d..feb3701 100644
--- a/core/modules/file/lib/Drupal/file/Tests/FileManagedUnitTestBase.php
+++ b/core/modules/file/lib/Drupal/file/Tests/FileManagedUnitTestBase.php
@@ -174,7 +174,9 @@ function createFile($filepath = NULL, $contents = NULL, $scheme = NULL) {
     // the hooks.
     $this->assertNotIdentical(drupal_write_record('file_managed', $file), FALSE, 'The file was added to the database.', 'Create test file');
 
-    return entity_create('file', (array) $file);
+    $file_entity = entity_create('file', (array) $file);
+    $file_entity->enforceIsNew(FALSE);
+    return $file_entity;
   }
 
   /**