diff --git a/core/modules/system/src/Form/ModulesListForm.php b/core/modules/system/src/Form/ModulesListForm.php
index eb894f6..6b6882b 100644
--- a/core/modules/system/src/Form/ModulesListForm.php
+++ b/core/modules/system/src/Form/ModulesListForm.php
@@ -239,6 +239,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     $form['actions']['submit'] = array(
       '#type' => 'submit',
       '#value' => $this->t('Save configuration'),
+      '#button_type' => 'primary',
     );
 
     return $form;