diff --git a/Documentation/Changelog/4.0.1.rst b/Documentation/Changelog/4.0.1.rst
new file mode 100644
index 0000000..171cf3d
--- /dev/null
+++ b/Documentation/Changelog/4.0.1.rst
@@ -0,0 +1,33 @@
+4.0.1
+=====
+
+Breaking
+--------
+
+Nothing
+
+Features
+--------
+
+Nothing
+
+Fixes
+-----
+
+* Add missing dependency to composer package `typo3/cms-install`.
+  As UpgradeWizards use API of the package.
+
+* Migrate deprecated PHPStan configuration options.
+
+* Adapt expected HTML output within functional tests.
+  As TYPO3 changed actual generated HTML.
+
+Tasks
+-----
+
+Nothing
+
+Deprecation
+-----------
+
+Nothing
diff --git a/Tests/Functional/Frontend/DatesTest.php b/Tests/Functional/Frontend/DatesTest.php
index 17b25dd..457ee23 100644
--- a/Tests/Functional/Frontend/DatesTest.php
+++ b/Tests/Functional/Frontend/DatesTest.php
@@ -198,8 +198,8 @@ class DatesTest extends AbstractFunctionalTestCase
         self::assertSame(200, $response->getStatusCode());
         $html = (string)$response->getBody();
 
-        self::assertStringContainsString('<meta name="description" content="Teaser of Event" />', $html);
-        self::assertStringContainsString('<meta name="keywords" content="Gewölbe, Goethe, Horst Damm, Kästner, Theater" />', $html);
+        self::assertStringContainsString('<meta name="description" content="Teaser of Event">', $html);
+        self::assertStringContainsString('<meta name="keywords" content="Gewölbe, Goethe, Horst Damm, Kästner, Theater">', $html);
     }
 
     #[Test]
@@ -211,9 +211,9 @@ class DatesTest extends AbstractFunctionalTestCase
         self::assertSame(200, $response->getStatusCode());
         $html = (string)$response->getBody();
 
-        self::assertStringContainsString('<meta property="og:title" content="Title of Event 15.02.2023 00:00" />', $html);
-        self::assertStringContainsString('<meta property="og:type" content="website" />', $html);
-        self::assertStringContainsString('<meta property="og:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif" />', $html);
+        self::assertStringContainsString('<meta property="og:title" content="Title of Event 15.02.2023 00:00">', $html);
+        self::assertStringContainsString('<meta property="og:type" content="website">', $html);
+        self::assertStringContainsString('<meta property="og:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif">', $html);
     }
 
     #[Test]
@@ -225,10 +225,10 @@ class DatesTest extends AbstractFunctionalTestCase
         self::assertSame(200, $response->getStatusCode());
         $html = (string)$response->getBody();
 
-        self::assertStringContainsString('<meta name="twitter:card" content="summary" />', $html);
-        self::assertStringContainsString('<meta name="twitter:title" content="Title of Event 15.02.2023 00:00" />', $html);
-        self::assertStringContainsString('<meta name="twitter:description" content="Teaser of Event" />', $html);
-        self::assertStringContainsString('<meta name="twitter:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif" />', $html);
+        self::assertStringContainsString('<meta name="twitter:card" content="summary">', $html);
+        self::assertStringContainsString('<meta name="twitter:title" content="Title of Event 15.02.2023 00:00">', $html);
+        self::assertStringContainsString('<meta name="twitter:description" content="Teaser of Event">', $html);
+        self::assertStringContainsString('<meta name="twitter:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif">', $html);
     }
 
     #[Test]
diff --git a/Tests/Functional/Frontend/EventsTest.php b/Tests/Functional/Frontend/EventsTest.php
index 5f0567d..b120ac4 100644
--- a/Tests/Functional/Frontend/EventsTest.php
+++ b/Tests/Functional/Frontend/EventsTest.php
@@ -54,8 +54,8 @@ class EventsTest extends AbstractFunctionalTestCase
         self::assertSame(200, $response->getStatusCode());
         $html = (string)$response->getBody();
 
-        self::assertStringContainsString('<meta name="description" content="Teaser of Event" />', $html);
-        self::assertStringContainsString('<meta name="keywords" content="Gewölbe, Goethe, Horst Damm, Kästner, Theater" />', $html);
+        self::assertStringContainsString('<meta name="description" content="Teaser of Event">', $html);
+        self::assertStringContainsString('<meta name="keywords" content="Gewölbe, Goethe, Horst Damm, Kästner, Theater">', $html);
     }
 
     #[Test]
@@ -67,9 +67,9 @@ class EventsTest extends AbstractFunctionalTestCase
         self::assertSame(200, $response->getStatusCode());
         $html = (string)$response->getBody();
 
-        self::assertStringContainsString('<meta property="og:title" content="Title of Event" />', $html);
-        self::assertStringContainsString('<meta property="og:type" content="website" />', $html);
-        self::assertStringContainsString('<meta property="og:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif" />', $html);
+        self::assertStringContainsString('<meta property="og:title" content="Title of Event">', $html);
+        self::assertStringContainsString('<meta property="og:type" content="website">', $html);
+        self::assertStringContainsString('<meta property="og:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif">', $html);
     }
 
     #[Test]
@@ -81,10 +81,10 @@ class EventsTest extends AbstractFunctionalTestCase
         self::assertSame(200, $response->getStatusCode());
         $html = (string)$response->getBody();
 
-        self::assertStringContainsString('<meta name="twitter:card" content="summary" />', $html);
-        self::assertStringContainsString('<meta name="twitter:title" content="Title of Event" />', $html);
-        self::assertStringContainsString('<meta name="twitter:description" content="Teaser of Event" />', $html);
-        self::assertStringContainsString('<meta name="twitter:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif" />', $html);
+        self::assertStringContainsString('<meta name="twitter:card" content="summary">', $html);
+        self::assertStringContainsString('<meta name="twitter:title" content="Title of Event">', $html);
+        self::assertStringContainsString('<meta name="twitter:description" content="Teaser of Event">', $html);
+        self::assertStringContainsString('<meta name="twitter:image" content="http://example.com/fileadmin/user_uploads/example-for-event.gif">', $html);
     }
 
     #[Test]
diff --git a/composer.json b/composer.json
index 16c9ec2..38ef959 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,8 @@
         "typo3/cms-filelist": "^12.4",
         "typo3/cms-filemetadata": "^12.4",
         "typo3/cms-fluid": "^12.4",
-        "typo3/cms-frontend": "^12.4"
+        "typo3/cms-frontend": "^12.4",
+        "typo3/cms-install": "^12.4"
     },
     "autoload": {
         "psr-4": {
diff --git a/ext_emconf.php b/ext_emconf.php
index 606cff6..f763d4b 100644
--- a/ext_emconf.php
+++ b/ext_emconf.php
@@ -9,7 +9,7 @@ $EM_CONF['events'] = [
     'author' => 'Dirk Koritnik, Daniel Siepmann',
     'author_email' => 'koritnik@werkraum-media.de, coding@daniel-siepmann.de',
     'state' => 'stable',
-    'version' => '4.0.0',
+    'version' => '4.0.1',
     'constraints' => [
         'depends' => [
             'typo3' => '',
diff --git a/phpstan.neon b/phpstan.neon
index b0c6ded..24dec12 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,10 +1,14 @@
 includes:
   - phpstan-baseline.neon
 parameters:
-    level: max
-    paths:
-        - Classes
-        - Configuration
-    checkMissingIterableValueType: false
-    checkGenericClassInNonGenericObjectType: false
-    reportUnmatchedIgnoredErrors: true
+  level: max
+  paths:
+    - Classes
+    - Configuration
+  reportUnmatchedIgnoredErrors: true
+
+  ignoreErrors:
+    -
+      identifier: missingType.generics
+    -
+      identifier: missingType.iterableValue