diff --git a/core/modules/views/src/Plugin/views/argument/ArgumentPluginBase.php b/core/modules/views/src/Plugin/views/argument/ArgumentPluginBase.php
index f9be2cd..c5849ec 100644
--- a/core/modules/views/src/Plugin/views/argument/ArgumentPluginBase.php
+++ b/core/modules/views/src/Plugin/views/argument/ArgumentPluginBase.php
@@ -1079,10 +1079,12 @@ public function getPlugin($type = 'argument_default', $name = NULL) {
         $options_name = 'default_argument_options';
         break;
       case 'argument_validator':
-        if ($this->options['specify_validation'] === 0) {
+        if (isset($this->options['specify_validation']) && $this->options['specify_validation'] === 0) {
           $plugin_name = 'none';
           $options_name = 'validate_options';
-          $this->options[$options_name] = array();
+          if (isset($this->options[$options_name])) {
+            $this->options[$options_name] = array();
+          }
           break;
         }
         if (!isset($this->options['validate']['type'])) {