diff --git a/app/views/admin/install/layout.php b/app/views/admin/install/layout.php
index 03e9a59f82ac400b8f53786e3a392845ab60d7e6..a3a227fabcadbd46460242d48519cd7a39397418 100644
--- a/app/views/admin/install/layout.php
+++ b/app/views/admin/install/layout.php
@@ -59,14 +59,14 @@
                 ) ?>
             <?php endif; ?>
 
-            <?php if (!$valid && $button_label): ?>
+            <?php if (!$valid && !empty($button_label)): ?>
                 <?= Studip\Button::create($button_label, 'continue') ?>
             <?php elseif (!$valid): ?>
                 <?= Studip\Button::create(_('Erneut prüfen'), 'check') ?>
             <?php elseif ($next_step): ?>
                 <?= Studip\Button::create($button_label ?? (_('Weiter') . ' >>'), 'continue') ?>
             <?php else: ?>
-                <?= Studip\Button::create($button_label, 'continue', ['style' => 'visibility: hidden;']) ?>
+                <?= Studip\Button::create($button_label ?? '', 'continue', ['style' => 'visibility: hidden;']) ?>
             <?php endif; ?>
             </div>
         </div>
diff --git a/lib/classes/SystemChecker.php b/lib/classes/SystemChecker.php
index 919114a12d53e8f2f52375911757cb8ef4322e83..0f6b5511035974e6870840b4db0a63a8b9d93f0c 100644
--- a/lib/classes/SystemChecker.php
+++ b/lib/classes/SystemChecker.php
@@ -113,7 +113,11 @@ final class SystemChecker
         $settings = [];
         $settings_valid = true;
         foreach ($requirements['settings'] as $setting => $state) {
-            $settings[$setting] = $this->compareSetting($variables[$setting], $state, $version['present']);
+            $settings[$setting] = $this->compareSetting(
+                $variables[$setting] ?? null,
+                $state,
+                $version['present']
+            );
 
             $settings_valid = $settings_valid && $settings[$setting]['valid'];
         }