diff --git a/core/modules/comment/comment.field.inc b/core/modules/comment/comment.field.inc
deleted file mode 100644
index 74593c6..0000000
--- a/core/modules/comment/comment.field.inc
+++ /dev/null
@@ -1,132 +0,0 @@
-<?php
-
-/**
- * @file
- * Enables comments with moderation on entities
- *
- * Provides a field and formatters to allow administrators to enable and
- * configure comments attached to entities.
- */
-use \Drupal\Core\Entity\EntityInterface;
-
-/**
- * Implements hook_field_info().
- */
-function comment_field_info() {
-  return array(
-    'comment' => array(
-      'label' => t('Comments'),
-      'description' => t('This field manages configuration and presentation of comments on an entity'),
-      'instance_settings' => array(
-        // Save this settings to allow other modules to migrate their data.
-        // @todo The "comment_default" formatter settings should used instead.
-        'default_mode' => COMMENT_MODE_THREADED,
-        'per_page' => 50,
-        'form_location' => COMMENT_FORM_BELOW,
-        // Comment form settings per field bundle.
-        'anonymous' => COMMENT_ANONYMOUS_MAYNOT_CONTACT,
-        'subject' => 1,
-        'preview' => DRUPAL_OPTIONAL,
-      ),
-      'default_widget' => 'comment_default',
-      'default_formatter' => 'comment_default',
-      'field item class' => 'Drupal\comment\Type\CommentItem',
-    )
-  );
-}
-
-/**
- * Implements hook_field_instance_settings_form().
- */
-function comment_field_instance_settings_form($field, $instance) {
-  $settings = $instance['settings'];
-  $form['comment'] = array(
-    '#type' => 'details',
-    '#title' => t('Comment form settings'),
-    '#collapsible' => TRUE,
-    '#collapsed' => FALSE,
-    '#field_name' => $field['field_name'],
-    '#process' => array('_comment_field_instance_settings_form_process'),
-    '#attributes' => array(
-      'class' => array('comment-instance-settings-form'),
-    ),
-    '#attached' => array(
-      'library' => array(array('comment', 'drupal.comment')),
-    ),
-  );
-  $form['comment']['default_mode'] = array(
-    '#type' => 'checkbox',
-    '#title' => t('Threading'),
-    '#default_value' => $settings['default_mode'],
-    '#description' => t('Show comment replies in a threaded list.'),
-  );
-  $form['comment']['per_page'] = array(
-    '#type' => 'select',
-    '#title' => t('Comments per page'),
-    '#default_value' => $settings['per_page'],
-    '#options' => _comment_per_page(),
-  );
-  $form['comment']['anonymous'] = array(
-    '#type' => 'select',
-    '#title' => t('Anonymous commenting'),
-    '#default_value' => $settings['anonymous'],
-    '#options' => array(
-      COMMENT_ANONYMOUS_MAYNOT_CONTACT => t('Anonymous posters may not enter their contact information'),
-      COMMENT_ANONYMOUS_MAY_CONTACT => t('Anonymous posters may leave their contact information'),
-      COMMENT_ANONYMOUS_MUST_CONTACT => t('Anonymous posters must leave their contact information'),
-    ),
-    '#access' => user_access('post comments', drupal_anonymous_user()),
-  );
-  $form['comment']['subject'] = array(
-    '#type' => 'checkbox',
-    '#title' => t('Allow comment title'),
-    '#default_value' => $settings['subject'],
-  );
-  $form['comment']['form_location'] = array(
-    '#type' => 'checkbox',
-    '#title' => t('Show reply form on the same page as comments'),
-    '#default_value' => $settings['form_location'],
-  );
-  $form['comment']['preview'] = array(
-    '#type' => 'radios',
-    '#title' => t('Preview comment'),
-    '#default_value' => $settings['preview'],
-    '#options' => array(
-      DRUPAL_DISABLED => t('Disabled'),
-      DRUPAL_OPTIONAL => t('Optional'),
-      DRUPAL_REQUIRED => t('Required'),
-    ),
-  );
-  return $form;
-}
-
-/**
- * Process callback to add submit handler for instance settings form.
- *
- * Attaches the required translation entity handlers for the instance which
- * correlates one to one with the comment bundle.
- */
-function _comment_field_instance_settings_form_process($element, $form_state) {
-  // Settings should not be stored as nested.
-  $parents = $element['#parents'];
-  array_pop($parents);
-  $element['#parents'] = $parents;
-  // Add translation entity handlers.
-  if (Drupal::moduleHandler()->moduleExists('translation_entity')) {
-    $comment_form = $element;
-    $comment_form_state['translation_entity']['key'] = 'language_configuration';
-    $element += translation_entity_enable_widget('comment', $element['#field_name'], $comment_form, $comment_form_state);
-    $element['translation_entity']['#parents'] = $element['translation_entity']['#array_parents'] = array(
-      'translation_entity'
-    );
-  }
-  return $element;
-}
-
-/**
- * Implements hook_field_is_empty().
- */
-function comment_field_is_empty($item, $field) {
-  // We always want the values saved so we can rely on them.
-  return FALSE;
-}
diff --git a/core/modules/comment/comment.install b/core/modules/comment/comment.install
index 0aa5938..ae780f0 100644
--- a/core/modules/comment/comment.install
+++ b/core/modules/comment/comment.install
@@ -332,22 +332,6 @@ function comment_schema() {
 }
 
 /**
- * Implements hook_field_schema().
- */
-function comment_field_schema($field) {
-  return array(
-    'columns' => array(
-      'status' => array(
-        'description' => 'Whether comments are allowed on this entity: 0 = no, 1 = closed (read only), 2 = open (read/write).',
-        'type' => 'int',
-        'not null' => TRUE,
-        'default' => 0,
-      ),
-    ),
-  );
-}
-
-/**
  * @addtogroup updates-7.x-to-8.x
  * @{
  */
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 1883799..7c7c7ed 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -21,9 +21,6 @@
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Drupal\Core\Language\Language;
 
-// Load all Field module hooks for Comment.
-require __DIR__ . '/comment.field.inc';
-
 /**
  * Comment is awaiting approval.
  */
@@ -2019,3 +2016,26 @@ function _comment_get_default_status($values) {
   // We only ever process first value if any.
   return isset($values[0]['status']) ? $values[0]['status'] : COMMENT_OPEN;
 }
+
+/**
+ * Process callback to add submit handler for instance settings form.
+ *
+ * Attaches the required translation entity handlers for the instance which
+ * correlates one to one with the comment bundle.
+ */
+function _comment_field_instance_settings_form_process($element, $form_state) {
+  // Settings should not be stored as nested.
+  $parents = $element['#parents'];
+  array_pop($parents);
+  $element['#parents'] = $parents;
+  // Add translation entity handlers.
+  if (Drupal::moduleHandler()->moduleExists('translation_entity')) {
+    $comment_form = $element;
+    $comment_form_state['translation_entity']['key'] = 'language_configuration';
+    $element += translation_entity_enable_widget('comment', $element['#field_name'], $comment_form, $comment_form_state);
+    $element['translation_entity']['#parents'] = $element['translation_entity']['#array_parents'] = array(
+      'translation_entity'
+    );
+  }
+  return $element;
+}
diff --git a/core/modules/comment/lib/Drupal/comment/Plugin/field/field_type/CommentItem.php b/core/modules/comment/lib/Drupal/comment/Plugin/field/field_type/CommentItem.php
new file mode 100644
index 0000000..4a21bba
--- /dev/null
+++ b/core/modules/comment/lib/Drupal/comment/Plugin/field/field_type/CommentItem.php
@@ -0,0 +1,162 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\comment\Plugin\field\field_type\CommentItem.
+ */
+
+namespace Drupal\comment\Plugin\field\field_type;
+
+use Drupal\Core\Annotation\Translation;
+use Drupal\Core\Entity\Annotation\FieldType;
+use Drupal\field\Plugin\Core\Entity\Field;
+use Drupal\field\Plugin\Type\FieldType\ConfigFieldItemBase;
+
+/**
+ * Plugin implementation of the 'comment' field type.
+ *
+ * @FieldType(
+ *   id = "comment",
+ *   module = "comment",
+ *   label = @Translation("Comments"),
+ *   description = @Translation("This field manages configuration and presentation of comments on an entity."),
+ *   settings = {
+ *     "max_length" = "255"
+ *   },
+ *   instance_settings = {
+ *     "default_mode" = COMMENT_MODE_THREADED,
+ *     "per_page" = 50,
+ *     "form_location" = COMMENT_FORM_BELOW,
+ *     "anonymous" = COMMENT_ANONYMOUS_MAYNOT_CONTACT,
+ *     "subject" = 1,
+ *     "preview" = DRUPAL_OPTIONAL,
+ *   },
+ *   default_widget = "comment_default",
+ *   default_formatter = "comment_default"
+ * )
+ */
+class CommentItem extends ConfigFieldItemBase {
+
+  /**
+   * Definitions of the contained properties.
+   *
+   * @var array
+   */
+  static $propertyDefinitions;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPropertyDefinitions() {
+    if (!isset(static::$propertyDefinitions)) {
+      static::$propertyDefinitions['status'] = array(
+        'type' => 'integer',
+        'label' => t('Comment status value'),
+        'settings' => array('default_value' => COMMENT_OPEN),
+      );
+    }
+    return static::$propertyDefinitions;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function schema(Field $field) {
+    return array(
+      'columns' => array(
+        'status' => array(
+          'description' => 'Whether comments are allowed on this entity: 0 = no, 1 = closed (read only), 2 = open (read/write).',
+          'type' => 'int',
+          'not null' => TRUE,
+          'default' => 0,
+        ),
+      ),
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function instanceSettingsForm(array $form, array &$form_state) {
+    $element = array();
+
+    $settings = $this->getInstance()->settings;
+    $field = $this->getInstance()->getField();
+
+    $element['comment'] = array(
+      '#type' => 'details',
+      '#title' => t('Comment form settings'),
+      '#collapsible' => TRUE,
+      '#collapsed' => FALSE,
+      '#field_name' => $field->id(),
+      '#process' => array('_comment_field_instance_settings_form_process'),
+      '#attributes' => array(
+        'class' => array('comment-instance-settings-form'),
+      ),
+      '#attached' => array(
+        'library' => array(array('comment', 'drupal.comment')),
+      ),
+    );
+    $element['comment']['default_mode'] = array(
+      '#type' => 'checkbox',
+      '#title' => t('Threading'),
+      '#default_value' => $settings['default_mode'],
+      '#description' => t('Show comment replies in a threaded list.'),
+    );
+    $element['comment']['per_page'] = array(
+      '#type' => 'select',
+      '#title' => t('Comments per page'),
+      '#default_value' => $settings['per_page'],
+      '#options' => _comment_per_page(),
+    );
+    $element['comment']['anonymous'] = array(
+      '#type' => 'select',
+      '#title' => t('Anonymous commenting'),
+      '#default_value' => $settings['anonymous'],
+      '#options' => array(
+        COMMENT_ANONYMOUS_MAYNOT_CONTACT => t('Anonymous posters may not enter their contact information'),
+        COMMENT_ANONYMOUS_MAY_CONTACT => t('Anonymous posters may leave their contact information'),
+        COMMENT_ANONYMOUS_MUST_CONTACT => t('Anonymous posters must leave their contact information'),
+      ),
+      '#access' => user_access('post comments', drupal_anonymous_user()),
+    );
+    $element['comment']['subject'] = array(
+      '#type' => 'checkbox',
+      '#title' => t('Allow comment title'),
+      '#default_value' => $settings['subject'],
+    );
+    $element['comment']['form_location'] = array(
+      '#type' => 'checkbox',
+      '#title' => t('Show reply form on the same page as comments'),
+      '#default_value' => $settings['form_location'],
+    );
+    $element['comment']['preview'] = array(
+      '#type' => 'radios',
+      '#title' => t('Preview comment'),
+      '#default_value' => $settings['preview'],
+      '#options' => array(
+        DRUPAL_DISABLED => t('Disabled'),
+        DRUPAL_OPTIONAL => t('Optional'),
+        DRUPAL_REQUIRED => t('Required'),
+      ),
+    );
+
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function applyDefaultValue($notify = TRUE) {
+    $this->setValue($this->getInstance()->default_value, $notify);
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isEmpty() {
+    // We always want the values saved so we can rely on them.
+    return FALSE;
+  }
+}
diff --git a/core/modules/comment/lib/Drupal/comment/Type/CommentItem.php b/core/modules/comment/lib/Drupal/comment/Type/CommentItem.php
deleted file mode 100644
index 642b5d3..0000000
--- a/core/modules/comment/lib/Drupal/comment/Type/CommentItem.php
+++ /dev/null
@@ -1,41 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\comment\Type\CommentItem.
- */
-
-namespace Drupal\comment\Type;
-
-use Drupal\Core\Entity\Field\FieldItemBase;
-
-/**
- * Defines the 'comment_field' entity field item.
- */
-class CommentItem extends FieldItemBase {
-
-  /**
-   * Property definitions of the contained properties.
-   *
-   * @see CommentItem::getPropertyDefinitions()
-   *
-   * @var array
-   */
-  static $propertyDefinitions;
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getPropertyDefinitions() {
-
-    if (!isset(static::$propertyDefinitions)) {
-      static::$propertyDefinitions['status'] = array(
-        'type' => 'integer',
-        'label' => t('Comment status value'),
-        'settings' => array('default_value' => COMMENT_OPEN),
-      );
-    }
-    return static::$propertyDefinitions;
-  }
-
-}