diff --git a/src/Helper/NavItemHelper.php b/src/Helper/NavItemHelper.php
index 76c9247..c00b971 100644
--- a/src/Helper/NavItemHelper.php
+++ b/src/Helper/NavItemHelper.php
@@ -21,7 +21,7 @@ public function __construct(array $item)
         $this->addClass('nav-link');
         $this->itemClass[] = 'nav-item';
 
-        if (! $this->item['subitems']) {
+        if (! ($this->item['subitems'] ?? null)) {
             return;
         }
 
diff --git a/src/Resources/contao/templates/nav_navbar.html5 b/src/Resources/contao/templates/nav_navbar.html5
index ab0a4bd..080f659 100644
--- a/src/Resources/contao/templates/nav_navbar.html5
+++ b/src/Resources/contao/templates/nav_navbar.html5
@@ -10,7 +10,7 @@
         <div class="dropdown-divider"></div>
         <?php endif ?>
         <<?= $itemHelper->getTag(); ?> <?= $itemHelper ?>><?php if ($item['isActive']): ?><?= $item['link']?><?php else: ?><span itemprop="name"><?= $item['link']?></span><?php endif; ?></<?= $itemHelper->getTag(); ?>>
-        <?= $item['subitems'] ?>
+        <?= $item['subitems'] ?? '' ?>
     <?php if ($helper->isLevel(1)): ?>
       </li>
     <?php endif; ?>