diff -u b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
--- b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
+++ b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
@@ -673,11 +673,11 @@
 
       $table_mapping = $this->getTableMapping();
       if ($this->revisionDataTable) {
-        // Find revisioned fields that are non-entity ID's
+        // Find revisioned fields that are not entity keys.
         $fields = array_diff($table_mapping->getFieldNames($this->revisionDataTable), $table_mapping->getFieldNames($this->baseTable));
 
-        // Find fields that are non-revisioned and non ID's. The value of
-        // data fields are persistent regardless of entity revision.
+        // Find fields that are not revisioned or entity keys. Data fields have
+        // the same value regardless of entity revision.
         $data_fields = array_diff($table_mapping->getFieldNames($this->dataTable), $fields, $table_mapping->getFieldNames($this->baseTable));
         if ($data_fields) {
           $fields = array_merge($fields, $data_fields);
diff -u b/core/modules/serialization/src/Tests/EntitySerializationTest.php b/core/modules/serialization/src/Tests/EntitySerializationTest.php
--- b/core/modules/serialization/src/Tests/EntitySerializationTest.php
+++ b/core/modules/serialization/src/Tests/EntitySerializationTest.php
@@ -59,7 +59,6 @@
         'value' => $this->randomMachineName(),
         'format' => 'full_html',
       ),
-      'persistent' => 33,
     );
     $this->entity = entity_create('entity_test_mulrev', $this->values);
     $this->entity->save();
@@ -101,8 +100,8 @@
           'format' => $this->values['field_test_text']['format'],
         ),
       ),
-      'persistent' => array(
-        array('value' => $this->values['persistent']),
+      'created' => array(
+        array('value' => $this->entity->created->value),
       ),
     );
 
@@ -156,7 +155,7 @@
       'user_id' => '<user_id><target_id>' . $this->values['user_id'] . '</target_id></user_id>',
       'revision_id' => '<revision_id><value>' . $this->entity->getRevisionId() . '</value></revision_id>',
       'field_test_text' => '<field_test_text><value>' . $this->values['field_test_text']['value'] . '</value><format>' . $this->values['field_test_text']['format'] . '</format></field_test_text>',
-      'persistent' => '<persistent><value>' . $this->values['persistent'] . '</value></persistent>',
+      'created' => '<created><value>' . $this->entity->created->value . '</value></created>',
     );
     // Sort it in the same order as normalised.
     $expected = array_merge($normalized, $expected);
diff -u b/core/modules/system/src/Tests/Entity/EntityRevisionsTest.php b/core/modules/system/src/Tests/Entity/EntityRevisionsTest.php
--- b/core/modules/system/src/Tests/Entity/EntityRevisionsTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityRevisionsTest.php
@@ -57,15 +57,14 @@
     $entity = entity_create($entity_type, array(
       'name' => 'foo',
       'user_id' => $this->web_user->id(),
-      'persistent' => $this->randomMachineName(32),
     ));
     $entity->field_test_text->value = 'bar';
     $entity->save();
 
     $names = array();
     $texts = array();
+    $created = array();
     $revision_ids = array();
-    $persistent = 0;
 
     // Create three revisions.
     $revision_count = 3;
@@ -78,7 +77,7 @@
       $entity->setNewRevision(TRUE);
       $names[] = $entity->name->value = $this->randomMachineName(32);
       $texts[] = $entity->field_test_text->value = $this->randomMachineName(32);
-      $persistent = $entity->persistent->value = $i * 2;
+      $created[] = $entity->created->value = time() + $i + 1;
       $entity->save();
       $revision_ids[] = $entity->revision_id->value;
 
@@ -98,8 +97,8 @@
       $this->assertEqual($entity_revision->field_test_text->value, $texts[$i], format_string('%entity_type: Text matches.', array('%entity_type' => $entity_type)));
 
       // Check non-revisioned values are loaded.
-      $this->assertTrue(isset($entity_revision->persistent->value), format_string('%entity_type: Non-revisioned field is loaded.', array('%entity_type' => $entity_type)));
-      $this->assertEqual($entity_revision->persistent->value, $persistent, format_string('%entity_type: Non-revisioned field value is the same between revisions.', array('%entity_type' => $entity_type)));
+      $this->assertTrue(isset($entity_revision->created->value), format_string('%entity_type: Non-revisioned field is loaded.', array('%entity_type' => $entity_type)));
+      $this->assertEqual($entity_revision->created->value, $created[2], format_string('%entity_type: Non-revisioned field value is the same between revisions.', array('%entity_type' => $entity_type)));
     }
 
     // Confirm the correct revision text appears in the edit form.
diff -u b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php
--- b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php
@@ -100,6 +100,10 @@
       ->setDescription(t('The bundle of the test entity.'))
       ->setRequired(TRUE);
 
+    $fields['created'] = BaseFieldDefinition::create('created')
+      ->setLabel(t('Authored on'))
+      ->setDescription(t('Time the entity was created'));
+
     $fields['user_id'] = BaseFieldDefinition::create('entity_reference')
       ->setLabel(t('User ID'))
       ->setDescription(t('The ID of the associated user.'))
@@ -120,12 +124,6 @@
         ),
       ));
 
-    // Create a non-revisioned field.
-    $fields['persistent'] = BaseFieldDefinition::create('integer')
-      ->setLabel(t('Persistent'))
-      ->setDescription(t('A field that does not have different values between revisions.'))
-      ->setReadOnly(TRUE);
-
     return $fields;
   }