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 117ade9..76157fb 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->get_plugin('argument_validator');
-    return $this->argument_validated = $plugin->validate_argument($arg);
+    return $this->argument_validated = $plugin->validateArgument($arg);
   }

   /**
@@ -960,7 +960,7 @@ public function validateArgument($arg) {
    * argument fails to validate, but there is an action to take anyway,
    * then validation cannot actually fail.
    */
-  function validate_argument($arg) {
+  function validateArgument($arg) {
     $validate_info = $this->default_actions($this->options['validate']['fail']);
     if (empty($validate_info['hard fail'])) {
       return TRUE;
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php
index e481552..d760821 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument_validator/ArgumentValidatorPluginBase.php
@@ -80,7 +80,7 @@ function check_access(&$form, $option_name) {
     }
   }

-  function validate_argument($arg) { return TRUE; }
+  function validateArgument($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 7a63069..1ef3667 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 validate_argument($argument) {
+  function validateArgument($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 6db339e..ee53f64 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 validate_argument($argument) {
+  function validateArgument($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 9b23895..c0c15d4 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 validate_argument($argument) {
+  function validateArgument($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/tests/views_test_config/test_views/views.view.test_simple_argument.yml b/core/modules/views/tests/views_test_config/test_views/views.view.test_simple_argument.yml
index 16cec76..043e304 100644
--- a/core/modules/views/tests/views_test_config/test_views/views.view.test_simple_argument.yml
+++ b/core/modules/views/tests/views_test_config/test_views/views.view.test_simple_argument.yml
@@ -66,7 +66,7 @@ display:
           default_argument_user: '0'
           default_argument_fixed: ''
           default_argument_php: ''
-          validate_argument_node_type:
+          validateArgument_node_type:
             page: '0'
             story: '0'
           validate_argument_node_access: '0'
diff --git a/core/modules/views/views.module b/core/modules/views/views.module
index 61826f8..cfbd3d4 100644
--- a/core/modules/views/views.module
+++ b/core/modules/views/views.module
@@ -414,7 +414,7 @@ function views_arg_load($value, $name, $display_id, $index) {

     if (isset($indexes[$index])) {
       if (isset($view->argument[$indexes[$index]])) {
-        $arg = $view->argument[$indexes[$index]]->validate_argument($value) ? $value : FALSE;
+        $arg = $view->argument[$indexes[$index]]->validateArgument($value) ? $value : FALSE;
         $view->destroy();

         // Store the output in case we load this same menu item again.