diff --git a/src/Plugin/views/filter/SearchApiFilterNumeric.php b/src/Plugin/views/filter/SearchApiFilterNumeric.php
index 9f67b30..74cec48 100644
--- a/src/Plugin/views/filter/SearchApiFilterNumeric.php
+++ b/src/Plugin/views/filter/SearchApiFilterNumeric.php
@@ -34,7 +34,7 @@ class SearchApiFilterNumeric extends NumericFilter {
   /**
    * {@inheritdoc}
    */
-  protected function opEmpty() {
+  protected function opEmpty($field) {
     $this->query->condition($this->realField, NULL, $this->operator == 'empty' ? '=' : '<>', $this->options['group']);
   }
 
diff --git a/src/Plugin/views/filter/SearchApiFilterTrait.php b/src/Plugin/views/filter/SearchApiFilterTrait.php
index 6cc782d..cb62d5a 100644
--- a/src/Plugin/views/filter/SearchApiFilterTrait.php
+++ b/src/Plugin/views/filter/SearchApiFilterTrait.php
@@ -15,13 +15,6 @@ use Drupal\search_api\Plugin\views\query\SearchApiQuery;
 trait SearchApiFilterTrait {
 
   /**
-   * The Views query the filter will work with.
-   *
-   * @var \Drupal\search_api\Plugin\views\query\SearchApiQuery
-   */
-  public $query;
-
-  /**
    * Constructs a filter object.
    */
   public function __construct() {
@@ -67,8 +60,8 @@ trait SearchApiFilterTrait {
    *   loaded.
    */
   protected function getIndex() {
-    if ($this->query) {
-      return $this->query->getIndex();
+    if ($this->getQuery()) {
+      return $this->getQuery()->getIndex();
     }
     $base_table = $this->view->storage->get('base_table');
     return SearchApiQuery::getIndexFromTable($base_table);
@@ -89,11 +82,21 @@ trait SearchApiFilterTrait {
     // @todo Use "IN"/"NOT IN" instead, once available.
     $conjunction = $this->operator == 'or' ? 'OR' : 'AND';
     $operator = $this->operator == 'not' ? '<>' : '=';
-    $filter = $this->query->createFilter($conjunction);
+    $filter = $this->getQuery()->createFilter($conjunction);
     foreach ($this->value as $value) {
       $filter->condition($this->realField, $value, $operator);
     }
-    $this->query->filter($filter, $this->options['group']);
+    $this->getQuery()->filter($filter, $this->options['group']);
+  }
+
+  /**
+   * Retrieves the query plugin.
+   *
+   * @return \Drupal\search_api\Plugin\views\query\SearchApiQuery
+   *   The query plugin.
+   */
+  public function getQuery() {
+    return $this->query;
   }
 
 }
diff --git a/src/Plugin/views/filter/SearchApiFulltext.php b/src/Plugin/views/filter/SearchApiFulltext.php
index 8747a6b..e5b2a6a 100644
--- a/src/Plugin/views/filter/SearchApiFulltext.php
+++ b/src/Plugin/views/filter/SearchApiFulltext.php
@@ -11,6 +11,7 @@ use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\Element;
 use Drupal\search_api\Entity\Index;
+use Drupal\views\Plugin\views\filter\FilterPluginBase;
 
 /**
  * Defines a filter for adding a fulltext search to the view.
@@ -19,39 +20,26 @@ use Drupal\search_api\Entity\Index;
  *
  * @ViewsFilter("search_api_fulltext")
  */
-class SearchApiFulltext extends SearchApiFilterText {
+class SearchApiFulltext extends FilterPluginBase {
+
+  use SearchApiFilterTrait;
 
   /**
    * {@inheritdoc}
    */
   public function showOperatorForm(&$form, FormStateInterface $form_state) {
-    $this->operatorForm($form, $form_state);
+    parent::showOperatorForm($form, $form_state);
     $form['operator']['#description'] = $this->t('This operator only applies when using "Search keys" as the "Use as" setting.');
   }
 
   /**
    * {@inheritdoc}
    */
-  public function operators() {
+  public function operatorOptions($which = 'title') {
     return array(
-      'and' => array(
-        'title' => $this->t('Contains all of these words'),
-        'method' => 'opFulltextSearch',
-        'short' => $this->t('and'),
-        'values' => 1,
-      ),
-      'or' => array(
-        'title' => $this->t('Contains any of these words'),
-        'method' => 'opFulltextSearch',
-        'short' => $this->t('or'),
-        'values' => 1,
-      ),
-      'not' => array(
-        'title' => $this->t('Contains none of these words'),
-        'method' => 'opFulltextSearch',
-        'short' => $this->t('not'),
-        'values' => 1,
-      ),
+      'and' => $this->t('Contains all of these words'),
+      'or' => $this->t('Contains any of these words'),
+      'not' => $this->t('Contains none of these words'),
     );
   }
 
@@ -120,6 +108,20 @@ class SearchApiFulltext extends SearchApiFilterText {
   /**
    * {@inheritdoc}
    */
+  protected function valueForm(&$form, FormStateInterface $form_state) {
+    parent::valueForm($form, $form_state);
+
+    $form['value'] = array(
+      '#type' => 'textfield',
+      '#title' => !$form_state->get('exposed') ? $this->t('Value') : '',
+      '#size' => 30,
+      '#default_value' => $this->value,
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function validateExposed(&$form, FormStateInterface $form_state) {
     // Only validate exposed input.
     if (empty($this->options['exposed']) || empty($this->options['expose']['identifier'])) {
@@ -132,7 +134,7 @@ class SearchApiFulltext extends SearchApiFilterText {
     }
 
     $identifier = $this->options['expose']['identifier'];
-    $input = &$form_state->getValues()[$identifier];
+    $input = &$form_state->getValue($identifier, '');
 
     if ($this->options['is_grouped'] && isset($this->options['group_info']['group_items'][$input])) {
       $this->operator = $this->options['group_info']['group_items'][$input]['operator'];
@@ -161,7 +163,7 @@ class SearchApiFulltext extends SearchApiFilterText {
   /**
    * {@inheritdoc}
    */
-  public function opFulltextSearch() {
+  public function query() {
     while (is_array($this->value)) {
       $this->value = $this->value ? reset($this->value) : '';
     }