diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/filter/Date.php b/core/modules/views/lib/Drupal/views/Plugin/views/filter/Date.php
index ace231da216a1fa37b7098c5f3a0e5f8ed72d923..9e961250eed11ddfca9512f51a553dc840052d1e 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/filter/Date.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/filter/Date.php
@@ -178,7 +178,7 @@ protected function opBetween($field) {
     $this->query->add_where_expression($this->options['group'], "$field $operator $a AND $b");
   }
 
-  function op_simple($field) {
+  protected function opSimple($field) {
     $value = intval(strtotime($this->value['value'], 0));
     if (!empty($this->value['type']) && $this->value['type'] == 'offset') {
       $value = '***CURRENT_TIME***' . sprintf('%+d', $value); // keep sign
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/filter/GroupByNumeric.php b/core/modules/views/lib/Drupal/views/Plugin/views/filter/GroupByNumeric.php
index 085775a150eb96777a1a0e17bfcabd2188f23384..cedae6dae1e66894026ff19fcc0b9ad31f0d3cb3 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/filter/GroupByNumeric.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/filter/GroupByNumeric.php
@@ -39,7 +39,7 @@ protected function opBetween($field) {
     }
   }
 
-  function op_simple($field) {
+  protected function opSimple($field) {
     $placeholder = $this->placeholder();
     $this->query->addHavingExpression($this->options['group'], "$field $this->operator $placeholder", array($placeholder => $this->value['value']));
   }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/filter/InOperator.php b/core/modules/views/lib/Drupal/views/Plugin/views/filter/InOperator.php
index 8b25654478894feef4ce71c8fd5d96f498e188ea..3b4b30084eed92a3716801fd41a409f39ef95f83 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/filter/InOperator.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/filter/InOperator.php
@@ -109,14 +109,14 @@ function operators() {
         'title' => t('Is one of'),
         'short' => t('in'),
         'short_single' => t('='),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'values' => 1,
       ),
       'not in' => array(
         'title' => t('Is not one of'),
         'short' => t('not in'),
         'short_single' => t('<>'),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'values' => 1,
       ),
     );
@@ -376,7 +376,7 @@ public function query() {
     }
   }
 
-  function op_simple() {
+  protected function opSimple() {
     if (empty($this->value)) {
       return;
     }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/filter/Numeric.php b/core/modules/views/lib/Drupal/views/Plugin/views/filter/Numeric.php
index 3ec2a849db509da053c3fd7f0a1a1881a67cdd89..f8e928bceb9647ae1f5f16d2a7ecc45e7dac23f6 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/filter/Numeric.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/filter/Numeric.php
@@ -39,37 +39,37 @@ function operators() {
     $operators = array(
       '<' => array(
         'title' => t('Is less than'),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'short' => t('<'),
         'values' => 1,
       ),
       '<=' => array(
         'title' => t('Is less than or equal to'),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'short' => t('<='),
         'values' => 1,
       ),
       '=' => array(
         'title' => t('Is equal to'),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'short' => t('='),
         'values' => 1,
       ),
       '!=' => array(
         'title' => t('Is not equal to'),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'short' => t('!='),
         'values' => 1,
       ),
       '>=' => array(
         'title' => t('Is greater than or equal to'),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'short' => t('>='),
         'values' => 1,
       ),
       '>' => array(
         'title' => t('Is greater than'),
-        'method' => 'op_simple',
+        'method' => 'opSimple',
         'short' => t('>'),
         'values' => 1,
       ),
@@ -260,7 +260,7 @@ protected function opBetween($field) {
     }
   }
 
-  function op_simple($field) {
+  protected function opSimple($field) {
     $this->query->add_where($this->options['group'], $field, $this->value['value'], $this->operator);
   }