diff --git a/CHANGELOG.md b/CHANGELOG.md
index 625099f..00a2a9d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -46,6 +46,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 - Drop the dependency of `roave/security-advisories`
 
 ### Fixed
+- Keep the global namespace clean in `ext_localconf.php` (#40)
 - Update the badge URLs in the README (#29, #22)
 - Fix code inspection warnings
 - Use the new annotations for lazy loading
diff --git a/ext_localconf.php b/ext_localconf.php
index 5f27f81..ee60ac5 100644
--- a/ext_localconf.php
+++ b/ext_localconf.php
@@ -1,16 +1,20 @@
 <?php
-// This makes the plugin available for front-end rendering.
-\TYPO3\CMS\Extbase\Utility\ExtensionUtility::configurePlugin(
-    // extension name, exactly matching the PHP namespaces (vendor and product)
-    'TTN.Tea',
-    // arbitrary, but unique plugin name (not visible in the BE)
-    'Tea',
-    // all actions
-    [
-        'Tea' => 'index, show',
-    ],
-    // non-cacheable actions
-    [
-        'Tea' => '',
-    ]
-);
+defined('TYPO3_MODE') or die('Access denied.');
+
+(static function () {
+    // This makes the plugin available for front-end rendering.
+    \TYPO3\CMS\Extbase\Utility\ExtensionUtility::configurePlugin(
+        // extension name, exactly matching the PHP namespaces (vendor and product)
+        'TTN.Tea',
+        // arbitrary, but unique plugin name (not visible in the BE)
+        'Tea',
+        // all actions
+        [
+            'Tea' => 'index, show',
+        ],
+        // non-cacheable actions
+        [
+            'Tea' => '',
+        ]
+    );
+})();