diff --git a/config/services.yaml b/config/services.yaml
index d1ed16a9..fbd340c1 100644
--- a/config/services.yaml
+++ b/config/services.yaml
@@ -93,6 +93,8 @@ services:
             '$bookFolderNamingFormat': '%BOOK_FOLDER_NAMING_FORMAT%'
             '$bookFileNamingFormat': '%BOOK_FILE_NAMING_FORMAT%'
 
+    App\Service\BookFileSystemManagerInterface: '@App\Service\BookFileSystemManager'
+
     App\Kobo\ParamConverter\SyncTokenParamConverter:
       tags:
         - { name: request.param_converter, priority: 100 }
@@ -124,4 +126,13 @@ services:
 
 when@dev:
     services:
-        Symfony\Component\HttpKernel\Profiler\Profiler: '@profiler'
\ No newline at end of file
+        Symfony\Component\HttpKernel\Profiler\Profiler: '@profiler'
+
+when@test:
+    services:
+        App\Tests\FileSystemManagerForTests:
+            autowire: true
+            bind:
+                $publicDirectory: '%kernel.project_dir%/tests/Resources'
+        App\Service\BookFileSystemManagerInterface:
+            alias: 'App\Tests\FileSystemManagerForTests'
\ No newline at end of file
diff --git a/src/Kobo/DownloadHelper.php b/src/Kobo/DownloadHelper.php
index fa057a0c..71202fa2 100644
--- a/src/Kobo/DownloadHelper.php
+++ b/src/Kobo/DownloadHelper.php
@@ -9,7 +9,7 @@
 use App\Kobo\Kepubify\KepubifyConversionFailed;
 use App\Kobo\Kepubify\KepubifyMessage;
 use App\Kobo\Response\MetadataResponseService;
-use App\Service\BookFileSystemManager;
+use App\Service\BookFileSystemManagerInterface;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\HttpFoundation\BinaryFileResponse;
 use Symfony\Component\HttpFoundation\HeaderUtils;
@@ -22,7 +22,7 @@
 class DownloadHelper
 {
     public function __construct(
-        private readonly BookFileSystemManager $fileSystemManager,
+        private readonly BookFileSystemManagerInterface $fileSystemManager,
         private readonly CoverTransformer $coverTransformer,
         protected UrlGeneratorInterface $urlGenerator,
         protected LoggerInterface $logger,
diff --git a/src/Service/BookFileSystemManager.php b/src/Service/BookFileSystemManager.php
index 05f0fdf7..0f2373e7 100644
--- a/src/Service/BookFileSystemManager.php
+++ b/src/Service/BookFileSystemManager.php
@@ -13,7 +13,7 @@
 use Symfony\Component\HttpFoundation\File\UploadedFile;
 use Symfony\Component\String\Slugger\SluggerInterface;
 
-class BookFileSystemManager
+class BookFileSystemManager implements BookFileSystemManagerInterface
 {
     public const ALLOWED_FILE_EXTENSIONS = [
         '*.epub', '*.cbr', '*.cbz', '*.pdf', '*.mobi',
diff --git a/src/Service/BookFileSystemManagerInterface.php b/src/Service/BookFileSystemManagerInterface.php
new file mode 100644
index 00000000..5d0f5ec8
--- /dev/null
+++ b/src/Service/BookFileSystemManagerInterface.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Service;
+
+use App\Entity\Book;
+
+interface BookFileSystemManagerInterface
+{
+    public function getBooksDirectory(): string;
+
+    public function getCoverDirectory(): string;
+
+    public function getBookFilename(Book $book): string;
+
+    public function getBookPublicPath(Book $book): string;
+
+    public function getCoverFilename(Book $book): ?string;
+
+    public function getBookSize(Book $book): ?int;
+
+    public function getCoverSize(Book $book): ?int;
+
+    public function fileExist(Book $book): bool;
+
+    public function coverExist(Book $book): bool;
+
+    public function getBookFile(Book $book): \SplFileInfo;
+}
diff --git a/src/Service/BookProgressionService.php b/src/Service/BookProgressionService.php
index 65af053f..9027fdca 100644
--- a/src/Service/BookProgressionService.php
+++ b/src/Service/BookProgressionService.php
@@ -12,7 +12,7 @@
 class BookProgressionService
 {
     public function __construct(
-        private BookFileSystemManager $fileSystemManager,
+        private BookFileSystemManagerInterface $fileSystemManager,
         private LoggerInterface $logger,
         private EntityManagerInterface $em,
     ) {
diff --git a/tests/Controller/Kobo/AbstractKoboControllerTest.php b/tests/Controller/Kobo/AbstractKoboControllerTest.php
index b946bd6a..a0580d7f 100644
--- a/tests/Controller/Kobo/AbstractKoboControllerTest.php
+++ b/tests/Controller/Kobo/AbstractKoboControllerTest.php
@@ -5,7 +5,6 @@
 use App\Kobo\Kepubify\KepubifyEnabler;
 use App\Kobo\Proxy\KoboProxyConfiguration;
 use App\Kobo\Proxy\KoboStoreProxy;
-use App\Tests\InjectFakeFileSystemTrait;
 use GuzzleHttp\Client;
 use GuzzleHttp\ClientInterface;
 use GuzzleHttp\Handler\MockHandler;
@@ -20,8 +19,6 @@
 
 abstract class AbstractKoboControllerTest extends WebTestCase
 {
-    use InjectFakeFileSystemTrait;
-
     protected ?string $accessKey = null;
     protected ?KoboDevice $koboDevice = null;
 
diff --git a/tests/Controller/Kobo/KoboDownloadControllerTest.php b/tests/Controller/Kobo/KoboDownloadControllerTest.php
index e865e3e7..67f0a72b 100644
--- a/tests/Controller/Kobo/KoboDownloadControllerTest.php
+++ b/tests/Controller/Kobo/KoboDownloadControllerTest.php
@@ -13,7 +13,6 @@ class KoboDownloadControllerTest extends AbstractKoboControllerTest
     public function testDownload(): void
     {
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
 
         $book = $this->findByIdAndKobo(BookFixture::ID, $this->getKoboDevice());
         self::assertNotNull($book, 'The book is not linked to the Kobo');
@@ -37,7 +36,6 @@ public function testDownload(): void
     public function testDownloadKepubFailed(): void
     {
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
 
         // Disable Kepubify conversion
         $lastValue = $this->getKepubifyEnabler()->disable();
@@ -63,8 +61,6 @@ public function testDownloadKepubFailed(): void
     public function testDownloadKepub(): void
     {
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
-
 
         $book = $this->findByIdAndKobo(BookFixture::ID, $this->getKoboDevice());
         self::assertNotNull($book, 'The book is not linked to the Kobo');
diff --git a/tests/Controller/Kobo/KoboImageControllerTest.php b/tests/Controller/Kobo/KoboImageControllerTest.php
index 18f33d11..c6168724 100644
--- a/tests/Controller/Kobo/KoboImageControllerTest.php
+++ b/tests/Controller/Kobo/KoboImageControllerTest.php
@@ -12,8 +12,6 @@ class KoboImageControllerTest extends AbstractKoboControllerTest
     public function testDownload(): void
     {
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
-
 
         $book = $this->findByIdAndKobo(BookFixture::ID, $this->getKoboDevice());
         self::assertNotNull($book, 'The book is not linked to the Kobo');
diff --git a/tests/Controller/Kobo/KoboSyncControllerTest.php b/tests/Controller/Kobo/KoboSyncControllerTest.php
index 805ddf36..8f84684f 100644
--- a/tests/Controller/Kobo/KoboSyncControllerTest.php
+++ b/tests/Controller/Kobo/KoboSyncControllerTest.php
@@ -30,7 +30,7 @@ public function assertPreConditions(): void
     public function testSyncControllerWithForce() : void
     {
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
+        
 
         $this->getEntityManager()->getRepository(KoboSyncedBook::class)->deleteAllSyncedBooks(1);
 
@@ -53,7 +53,7 @@ public function testSyncControllerWithForce() : void
     public function testSyncControllerWithoutForce() : void
     {
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
+        
 
         $client?->request('GET', '/kobo/'.$this->accessKey.'/v1/library/sync');
 
@@ -90,7 +90,6 @@ public function testSyncControllerWithRemote() : void
                 }
             }]'));
 
-        $this->injectFakeFileSystemManager();
 
         $client?->request('GET', '/kobo/'.$this->accessKey.'/v1/library/sync');
 
@@ -112,7 +111,6 @@ public function testSyncControllerMetadata() : void
     {
         $uuid = $this->getBook()->getUuid();
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
         $this->getKepubifyEnabler()->disable();
 
         $client?->request('GET', '/kobo/'.$this->accessKey.'/v1/library/'.$uuid."/metadata");
@@ -128,7 +126,6 @@ public function testSyncControllerMetadataWithConversion() : void
     {
         $uuid = $this->getBook()->getUuid();
         $client = static::getClient();
-        $this->injectFakeFileSystemManager();
         self::assertTrue($this->getKepubifyEnabler()->isEnabled());
 
         $client?->request('GET', '/kobo/'.$this->accessKey.'/v1/library/'.$uuid."/metadata");
diff --git a/tests/FileSystemManagerForTests.php b/tests/FileSystemManagerForTests.php
new file mode 100644
index 00000000..18693bfd
--- /dev/null
+++ b/tests/FileSystemManagerForTests.php
@@ -0,0 +1,26 @@
+<?php
+namespace App\Tests;
+
+use App\Service\BookFileSystemManager;
+use Psr\Log\LoggerInterface;
+use Symfony\Bundle\SecurityBundle\Security;
+use Symfony\Component\String\Slugger\SluggerInterface;
+
+class FileSystemManagerForTests extends BookFileSystemManager
+{
+    public function __construct(
+        Security $security,
+        SluggerInterface $slugger,
+        LoggerInterface $logger,
+        protected string $publicDirectory,
+    ){
+        parent::__construct(
+            $security,
+            $publicDirectory,
+            '{authorFirst}/{author}/{serie}/{title}',
+            '{serie}-{serieIndex}-{title}',
+            $slugger,
+            $logger
+        );
+    }
+}
\ No newline at end of file
diff --git a/tests/InjectFakeFileSystemTrait.php b/tests/InjectFakeFileSystemTrait.php
index 70bac248..ac7e72d8 100644
--- a/tests/InjectFakeFileSystemTrait.php
+++ b/tests/InjectFakeFileSystemTrait.php
@@ -1,40 +1,8 @@
 <?php
 namespace App\Tests;
 
-use App\DataFixtures\BookFixture;
-use App\Service\BookFileSystemManager;
-use Psr\Log\NullLogger;
-use Symfony\Bundle\SecurityBundle\Security;
-use Symfony\Component\String\Slugger\SluggerInterface;
-
 trait InjectFakeFileSystemTrait
 {
     public function injectFakeFileSystemManager(): void
-    {
-        $resources = __DIR__.'/Resources';
-        $realPath = realpath($resources);
-        self::assertNotFalse($realPath);
-        $fixtureBookPath = $realPath."/";
-        $mockBuilder = $this->getMockBuilder(BookFileSystemManager::class);
-
-        $DEFAULT_BOOK_FOLDER_NAMING_FORMAT = '{authorFirst}/{author}/{title}/{serie}';
-        $DEFAULT_BOOK_FILE_NAMING_FORMAT = '{serie}-{title}';
-
-        $mock =  $mockBuilder->setConstructorArgs([
-            self::getContainer()->get(Security::class),
-            realpath($resources),
-            $DEFAULT_BOOK_FOLDER_NAMING_FORMAT,
-            $DEFAULT_BOOK_FILE_NAMING_FORMAT,
-            $this->createMock(SluggerInterface::class),
-            new NullLogger(),
-        ])
-            ->onlyMethods(['getBooksDirectory', 'getCoverDirectory'])
-            ->enableProxyingToOriginalMethods()
-            ->getMock();
-        $mock->expects(self::any())->method('getBooksDirectory')->willReturn($fixtureBookPath);
-        $mock->expects(self::any())->method('getCoverDirectory')->willReturn($fixtureBookPath);
-
-        self::assertSame(realpath($resources).'/books/'.BookFixture::BOOK_ODYSSEY_FILENAME, $mock->getBookFilename($this->getBook()), "Faking Filesystem failed");
-        self::getContainer()->set(BookFileSystemManager::class, $mock);
-    }
+    {}
 }
\ No newline at end of file
diff --git a/tests/Service/BookProgressionServiceTest.php b/tests/Service/BookProgressionServiceTest.php
index b07ce6f2..1fa9cb5e 100644
--- a/tests/Service/BookProgressionServiceTest.php
+++ b/tests/Service/BookProgressionServiceTest.php
@@ -10,18 +10,15 @@
 use App\Repository\BookRepository;
 use App\Repository\UserRepository;
 use App\Service\BookProgressionService;
-use App\Tests\InjectFakeFileSystemTrait;
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
 
 class BookProgressionServiceTest extends KernelTestCase
 {
-    use InjectFakeFileSystemTrait;
     protected function setUp(): void
     {
         parent::setUp();
 
         self::bootKernel();
-        $this->injectFakeFileSystemManager();
     }
 
     public function testPageNumber(): void{