diff --git a/CHANGELOG.md b/CHANGELOG.md
index a12e8d8..65bdb67 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 - Composer script for PHP linting
 
 ### Changed
+- Convert the PHP namespaces to "TTN" (#8)
 - Update the contact email in the CoC document (#6)
 - Switch to the `TTN` PHP vendor namespace (#1, #5)
 - Sort the Composer dependencies
diff --git a/Classes/Controller/TeaController.php b/Classes/Controller/TeaController.php
index ab0d46e..4282dd0 100644
--- a/Classes/Controller/TeaController.php
+++ b/Classes/Controller/TeaController.php
@@ -1,10 +1,10 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Controller;
+namespace TTN\Tea\Controller;
 
-use OliverKlee\Tea\Domain\Model\Product\Tea;
-use OliverKlee\Tea\Domain\Repository\Product\TeaRepository;
+use TTN\Tea\Domain\Model\Product\Tea;
+use TTN\Tea\Domain\Repository\Product\TeaRepository;
 use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
 
 /**
diff --git a/Classes/Domain/Model/Product/Tea.php b/Classes/Domain/Model/Product/Tea.php
index 81f5627..ab09c9e 100644
--- a/Classes/Domain/Model/Product/Tea.php
+++ b/Classes/Domain/Model/Product/Tea.php
@@ -1,7 +1,7 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Domain\Model\Product;
+namespace TTN\Tea\Domain\Model\Product;
 
 use TYPO3\CMS\Extbase\Annotation\ORM\Lazy;
 use TYPO3\CMS\Extbase\Domain\Model\FileReference;
diff --git a/Classes/Domain/Repository/Product/TeaRepository.php b/Classes/Domain/Repository/Product/TeaRepository.php
index bc04297..7e4c196 100644
--- a/Classes/Domain/Repository/Product/TeaRepository.php
+++ b/Classes/Domain/Repository/Product/TeaRepository.php
@@ -1,9 +1,9 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Domain\Repository\Product;
+namespace TTN\Tea\Domain\Repository\Product;
 
-use OliverKlee\Tea\Domain\Repository\Traits\StoragePageAgnosticTrait;
+use TTN\Tea\Domain\Repository\Traits\StoragePageAgnosticTrait;
 use TYPO3\CMS\Extbase\Persistence\QueryInterface;
 use TYPO3\CMS\Extbase\Persistence\Repository;
 
diff --git a/Classes/Domain/Repository/Traits/StoragePageAgnosticTrait.php b/Classes/Domain/Repository/Traits/StoragePageAgnosticTrait.php
index 19e56fb..bb65200 100644
--- a/Classes/Domain/Repository/Traits/StoragePageAgnosticTrait.php
+++ b/Classes/Domain/Repository/Traits/StoragePageAgnosticTrait.php
@@ -1,7 +1,7 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Domain\Repository\Traits;
+namespace TTN\Tea\Domain\Repository\Traits;
 
 use TYPO3\CMS\Extbase\Object\ObjectManagerInterface;
 use TYPO3\CMS\Extbase\Persistence\Generic\QuerySettingsInterface;
diff --git a/Configuration/TCA/Overrides/tt_content.php b/Configuration/TCA/Overrides/tt_content.php
index 3906beb..42b47c8 100644
--- a/Configuration/TCA/Overrides/tt_content.php
+++ b/Configuration/TCA/Overrides/tt_content.php
@@ -4,7 +4,7 @@ defined('TYPO3_MODE') or die();
 // This makes the plugin selectable in the BE.
 \TYPO3\CMS\Extbase\Utility\ExtensionUtility::registerPlugin(
     // extension name, exactly matching the PHP namespaces (vendor and product)
-    'OliverKlee.Tea',
+    'TTN.Tea',
     // arbitrary, but unique plugin name (not visible in the BE)
     'Tea',
     // plugin title, as visible in the drop-down in the BE
diff --git a/Tests/Acceptance/StarterCest.php b/Tests/Acceptance/StarterCest.php
index 12864c3..901335a 100644
--- a/Tests/Acceptance/StarterCest.php
+++ b/Tests/Acceptance/StarterCest.php
@@ -1,7 +1,7 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Tests\Acceptance;
+namespace TTN\Tea\Tests\Acceptance;
 
 /**
  * Test case.
diff --git a/Tests/Functional/Controller/TeaControllerTest.php b/Tests/Functional/Controller/TeaControllerTest.php
index 7c1f6da..98cd024 100644
--- a/Tests/Functional/Controller/TeaControllerTest.php
+++ b/Tests/Functional/Controller/TeaControllerTest.php
@@ -1,7 +1,7 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Tests\Functional\Controller;
+namespace TTN\Tea\Tests\Functional\Controller;
 
 use Nimut\TestingFramework\TestCase\FunctionalTestCase;
 
diff --git a/Tests/Functional/Domain/Repository/Product/TeaRepositoryTest.php b/Tests/Functional/Domain/Repository/Product/TeaRepositoryTest.php
index e19c42f..8c3b578 100644
--- a/Tests/Functional/Domain/Repository/Product/TeaRepositoryTest.php
+++ b/Tests/Functional/Domain/Repository/Product/TeaRepositoryTest.php
@@ -1,11 +1,11 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Tests\Functional\Domain\Repository\Product;
+namespace TTN\Tea\Tests\Functional\Domain\Repository\Product;
 
 use Nimut\TestingFramework\TestCase\FunctionalTestCase;
-use OliverKlee\Tea\Domain\Model\Product\Tea;
-use OliverKlee\Tea\Domain\Repository\Product\TeaRepository;
+use TTN\Tea\Domain\Model\Product\Tea;
+use TTN\Tea\Domain\Repository\Product\TeaRepository;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Extbase\Domain\Model\FileReference;
 use TYPO3\CMS\Extbase\Object\ObjectManager;
diff --git a/Tests/Unit/Controller/TeaControllerTest.php b/Tests/Unit/Controller/TeaControllerTest.php
index bc69085..c5a4a07 100644
--- a/Tests/Unit/Controller/TeaControllerTest.php
+++ b/Tests/Unit/Controller/TeaControllerTest.php
@@ -1,12 +1,12 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Tests\Unit\Controller;
+namespace TTN\Tea\Tests\Unit\Controller;
 
 use Nimut\TestingFramework\TestCase\UnitTestCase;
-use OliverKlee\Tea\Controller\TeaController;
-use OliverKlee\Tea\Domain\Model\Product\Tea;
-use OliverKlee\Tea\Domain\Repository\Product\TeaRepository;
+use TTN\Tea\Controller\TeaController;
+use TTN\Tea\Domain\Model\Product\Tea;
+use TTN\Tea\Domain\Repository\Product\TeaRepository;
 use Prophecy\Prophecy\ObjectProphecy;
 use Prophecy\Prophecy\ProphecySubjectInterface;
 use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
diff --git a/Tests/Unit/Domain/Model/Product/TeaTest.php b/Tests/Unit/Domain/Model/Product/TeaTest.php
index 8a4e31e..461364a 100644
--- a/Tests/Unit/Domain/Model/Product/TeaTest.php
+++ b/Tests/Unit/Domain/Model/Product/TeaTest.php
@@ -1,10 +1,10 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Tests\Unit\Domain\Model\Product;
+namespace TTN\Tea\Tests\Unit\Domain\Model\Product;
 
 use Nimut\TestingFramework\TestCase\UnitTestCase;
-use OliverKlee\Tea\Domain\Model\Product\Tea;
+use TTN\Tea\Domain\Model\Product\Tea;
 use TYPO3\CMS\Extbase\Domain\Model\FileReference;
 use TYPO3\CMS\Extbase\DomainObject\AbstractEntity;
 
diff --git a/Tests/Unit/Domain/Repository/Product/TeaRepositoryTest.php b/Tests/Unit/Domain/Repository/Product/TeaRepositoryTest.php
index a987865..1f6dfeb 100644
--- a/Tests/Unit/Domain/Repository/Product/TeaRepositoryTest.php
+++ b/Tests/Unit/Domain/Repository/Product/TeaRepositoryTest.php
@@ -1,10 +1,10 @@
 <?php
 declare(strict_types=1);
 
-namespace OliverKlee\Tea\Tests\Unit\Domain\Repository\Product;
+namespace TTN\Tea\Tests\Unit\Domain\Repository\Product;
 
 use Nimut\TestingFramework\TestCase\UnitTestCase;
-use OliverKlee\Tea\Domain\Repository\Product\TeaRepository;
+use TTN\Tea\Domain\Repository\Product\TeaRepository;
 use Prophecy\Prophecy\ProphecySubjectInterface;
 use TYPO3\CMS\Extbase\Object\ObjectManagerInterface;
 use TYPO3\CMS\Extbase\Persistence\Repository;
diff --git a/composer.json b/composer.json
index 4dffda4..bfbe228 100644
--- a/composer.json
+++ b/composer.json
@@ -46,12 +46,12 @@
     },
     "autoload": {
         "psr-4": {
-            "OliverKlee\\Tea\\": "Classes/"
+            "TTN\\Tea\\": "Classes/"
         }
     },
     "autoload-dev": {
         "psr-4": {
-            "OliverKlee\\Tea\\Tests\\": "Tests/"
+            "TTN\\Tea\\Tests\\": "Tests/"
         }
     },
     "prefer-stable": true,
diff --git a/ext_emconf.php b/ext_emconf.php
index 68d4669..53be2f6 100644
--- a/ext_emconf.php
+++ b/ext_emconf.php
@@ -18,12 +18,12 @@ $EM_CONF[$_EXTKEY] = [
     'author_company' => 'TYPO3 Trainer Network',
     'autoload' => [
         'psr-4' => [
-            'OliverKlee\\Tea\\' => 'Classes/',
+            'TTN\\Tea\\' => 'Classes/',
         ],
     ],
     'autoload-dev' => [
         'psr-4' => [
-            'OliverKlee\\Tea\\Tests\\' => 'Tests/',
+            'TTN\\Tea\\Tests\\' => 'Tests/',
         ],
     ],
 ];
diff --git a/ext_localconf.php b/ext_localconf.php
index 749e7fe..5f27f81 100644
--- a/ext_localconf.php
+++ b/ext_localconf.php
@@ -2,7 +2,7 @@
 // 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)
-    'OliverKlee.Tea',
+    'TTN.Tea',
     // arbitrary, but unique plugin name (not visible in the BE)
     'Tea',
     // all actions