diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php
index d0d2729..7649fc6 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php
@@ -950,7 +950,7 @@ public function validateArgument($arg) {
     }
 
     $plugin = $this->getPlugin('argument_validator');
-    return $this->argument_validated = $plugin->validateArgument($arg);
+    return $this->argument_validated = $plugin->validate_argument($arg);
   }
 
   /**
@@ -960,7 +960,7 @@ public function validateArgument($arg) {
    * argument fails to validate, but there is an action to take anyway,
    * then validation cannot actually fail.
    */
-  function validateArgument($arg) {
+  function validate_argument($arg) {
     $validate_info = $this->defaultActions($this->options['validate']['fail']);
     if (empty($validate_info['hard fail'])) {
       return TRUE;
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php
index 297703d..e7945dc 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php
@@ -80,7 +80,7 @@ protected function checkAccess(&$form, $option_name) {
     }
   }
 
-  function validateArgument($arg) { return TRUE; }
+  function validate_argument($arg) { return TRUE; }
 
   /**
    * Process the summary arguments for displaying.
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/None.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/None.php
index 1ef3667..7a63069 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/None.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/None.php
@@ -22,7 +22,7 @@
  */
 class None extends ArgumentValidatorPluginBase {
 
-  function validateArgument($argument) {
+  function validate_argument($argument) {
     if (!empty($this->argument->options['must_not_be'])) {
       return !isset($argument);
     }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Numeric.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Numeric.php
index ee53f64..6db339e 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Numeric.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Numeric.php
@@ -22,7 +22,7 @@
  */
 class Numeric extends ArgumentValidatorPluginBase {
 
-  function validateArgument($argument) {
+  function validate_argument($argument) {
     return is_numeric($argument);
   }
 
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Php.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Php.php
index 82c1f65..dc16a1c 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Php.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/Php.php
@@ -49,7 +49,7 @@ public function access() {
     return user_access('use PHP for settings');
   }
 
-  function validateArgument($argument) {
+  function validate_argument($argument) {
     // set up variables to make it easier to reference during the argument.
     $view = &$this->view;
     $handler = &$this->argument;
diff --git a/core/modules/views/views.module b/core/modules/views/views.module
index e446570..d755506 100644
--- a/core/modules/views/views.module
+++ b/core/modules/views/views.module
@@ -404,7 +404,7 @@ function views_arg_load($value, $name, $display_id, $index) {
 
     if (isset($indexes[$index])) {
       if (isset($view->argument[$indexes[$index]])) {
-        $arg = $view->argument[$indexes[$index]]->validateArgument($value) ? $value : FALSE;
+        $arg = $view->argument[$indexes[$index]]->validate_argument($value) ? $value : FALSE;
         $view->destroy();
 
         // Store the output in case we load this same menu item again.