diff --git a/core/modules/action/src/ActionFormBase.php b/core/modules/action/src/ActionFormBase.php
index 0b972d4..5f67ad6 100644
--- a/core/modules/action/src/ActionFormBase.php
+++ b/core/modules/action/src/ActionFormBase.php
@@ -79,6 +79,7 @@ public function form(array $form, FormStateInterface $form_state) {
       '#description' => $this->t('A unique name for this action. It must only contain lowercase letters, numbers and underscores.'),
       '#machine_name' => array(
         'exists' => array($this, 'exists'),
+        'replace_pattern' => '[^a-z0-9_\.]+',
       ),
     );
     $form['plugin'] = array(