diff --git a/core/modules/update/src/Form/UpdateManagerInstall.php b/core/modules/update/src/Form/UpdateManagerInstall.php
index b3e2deb..43d1f62 100644
--- a/core/modules/update/src/Form/UpdateManagerInstall.php
+++ b/core/modules/update/src/Form/UpdateManagerInstall.php
@@ -104,6 +104,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     $form['actions'] = array('#type' => 'actions');
     $form['actions']['submit'] = array(
       '#type' => 'submit',
+      '#button_type' => 'primary',
       '#value' => $this->t('Install'),
     );