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 c1d7724..683761e 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
@@ -96,7 +96,7 @@ function uses_breadcrumb() {
     return !empty($info['breadcrumb']);
   }
 
-  function is_exception($arg = NULL) {
+  protected function isException($arg = NULL) {
     if (!isset($arg)) {
       $arg = isset($this->argument) ? $this->argument : NULL;
     }
@@ -945,7 +945,7 @@ public function validateArgument($arg) {
       return $this->argument_validated;
     }
 
-    if ($this->is_exception($arg)) {
+    if ($this->isException($arg)) {
       return $this->argument_validated = TRUE;
     }
 
diff --git a/core/modules/views/lib/Drupal/views/ViewExecutable.php b/core/modules/views/lib/Drupal/views/ViewExecutable.php
index 3daed62..84ca03b 100644
--- a/core/modules/views/lib/Drupal/views/ViewExecutable.php
+++ b/core/modules/views/lib/Drupal/views/ViewExecutable.php
@@ -872,7 +872,7 @@ protected function _buildArguments() {
           break;
         }
 
-        if ($argument->is_exception()) {
+        if ($argument->isException()) {
           $arg_title = $argument->exception_title();
         }
         else {