diff --git a/core/modules/node/lib/Drupal/node/Plugin/views/filter/Access.php b/core/modules/node/lib/Drupal/node/Plugin/views/filter/Access.php
index f9e66b9..bf09edf 100644
--- a/core/modules/node/lib/Drupal/node/Plugin/views/filter/Access.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/views/filter/Access.php
@@ -20,7 +20,7 @@
 class Access extends FilterPluginBase {
 
   public function adminSummary() { }
-  function operator_form(&$form, &$form_state) { }
+  public function operatorForm(&$form, &$form_state) { }
   public function canExpose() {
     return FALSE;
   }
diff --git a/core/modules/node/lib/Drupal/node/Plugin/views/filter/Status.php b/core/modules/node/lib/Drupal/node/Plugin/views/filter/Status.php
index 3ae361e..aed1ae0 100644
--- a/core/modules/node/lib/Drupal/node/Plugin/views/filter/Status.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/views/filter/Status.php
@@ -21,7 +21,7 @@ class Status extends FilterPluginBase {
 
   public function adminSummary() { }
 
-  function operator_form(&$form, &$form_state) { }
+  public function operatorForm(&$form, &$form_state) { }
 
   public function canExpose() { return FALSE; }
 
diff --git a/core/modules/search/lib/Drupal/search/Plugin/views/filter/Search.php b/core/modules/search/lib/Drupal/search/Plugin/views/filter/Search.php
index afb7724..cb81b68 100644
--- a/core/modules/search/lib/Drupal/search/Plugin/views/filter/Search.php
+++ b/core/modules/search/lib/Drupal/search/Plugin/views/filter/Search.php
@@ -48,7 +48,7 @@ protected function defineOptions() {
   /**
    * Provide simple equality operator
    */
-  function operator_form(&$form, &$form_state) {
+  public function operatorForm(&$form, &$form_state) {
     $form['operator'] = array(
       '#type' => 'radios',
       '#title' => t('On empty input'),
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/filter/BooleanOperator.php b/core/modules/views/lib/Drupal/views/Plugin/views/filter/BooleanOperator.php
index e5327f1..ad17dda 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/filter/BooleanOperator.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/filter/BooleanOperator.php
@@ -96,7 +96,7 @@ protected function defineOptions() {
     return $options;
   }
 
-  function operator_form(&$form, &$form_state) {
+  function operatorForm(&$form, &$form_state) {
     $form['operator'] = array();
   }
 
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/filter/FilterPluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/filter/FilterPluginBase.php
index e0dd2d5..85d18bc 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/filter/FilterPluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/filter/FilterPluginBase.php
@@ -216,7 +216,7 @@ public function buildOptionsForm(&$form, &$form_state) {
       }
     }
     else {
-      // Add the subform from operator_form().
+      // Add the subform from operatorForm().
       $this->show_operator_form($form, $form_state);
       // Add the subform from value_form().
       $this->show_value_form($form, $form_state);
@@ -266,7 +266,7 @@ public function submitOptionsForm(&$form, &$form_state) {
    * Shortcut to display the operator form.
    */
   function show_operator_form(&$form, &$form_state) {
-    $this->operator_form($form, $form_state);
+    $this->operatorForm($form, $form_state);
     $form['operator']['#prefix'] = '<div class="views-group-box views-left-30">';
     $form['operator']['#suffix'] = '</div>';
   }
@@ -279,7 +279,7 @@ function show_operator_form(&$form, &$form_state) {
    *
    * @see buildOptionsForm()
    */
-  function operator_form(&$form, &$form_state) {
+  public function operatorForm(&$form, &$form_state) {
     $options = $this->operator_options();
     if (!empty($options)) {
       $form['operator'] = array(
@@ -787,7 +787,7 @@ public function buildExposedForm(&$form, &$form_state) {
     // Build the exposed form, when its based on an operator.
     if (!empty($this->options['expose']['use_operator']) && !empty($this->options['expose']['operator_id'])) {
       $operator = $this->options['expose']['operator_id'];
-      $this->operator_form($form, $form_state);
+      $this->operatorForm($form, $form_state);
       $form[$operator] = $form['operator'];
 
       if (isset($form[$operator]['#title'])) {
@@ -962,7 +962,7 @@ function build_group_form(&$form, &$form_state) {
       // $row acts as a fake form to render each widget in a row.
       $row = array();
       $groups[$item_id] = '';
-      $this->operator_form($row, $form_state);
+      $this->operatorForm($row, $form_state);
       // Force the operator form to be a select box. Some handlers uses
       // radios and they occupy a lot of space in a table row.
       $row['operator']['#type'] = 'select';