diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 12497dc4..c25b8626 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -9,14 +9,26 @@ on:
 
 jobs:
   tests:
-    name: Tests (PHP ${{ matrix.php-version }}, Composer ${{ matrix.composer-version }} & ${{ matrix.dependencies }} dependencies)
-    runs-on: ubuntu-latest
+    name: Tests (PHP ${{ matrix.php-version }}, Composer ${{ matrix.composer-version }} & ${{ matrix.dependencies }} dependencies on ${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         php-version: ["8.1", "8.2", "8.3"]
         composer-version: ["2.1", "2.2", "2.3", "2.4", "2.5", "2.6", "2.7"]
         dependencies: ["highest", "lowest"]
+        os: ["ubuntu-latest"]
+        include:
+          # Windows tests
+          - php-version: "8.3"
+            composer-version: "2.7"
+            dependencies: "highest"
+            os: "windows-latest"
+          # macOS tests
+          - php-version: "8.3"
+            composer-version: "2.7"
+            dependencies: "highest"
+            os: "macos-latest"
     steps:
       - uses: actions/checkout@v4
         with:
@@ -28,6 +40,7 @@ jobs:
         with:
           php-version: ${{ matrix.php-version }}
           tools: composer:v${{ matrix.composer-version }}
+          extensions: sockets
           coverage: none
 
       # Install dependencies
@@ -36,7 +49,7 @@ jobs:
         with:
           dependency-versions: ${{ matrix.dependencies }}
           # Composer < 2.7 is not compatible with symfony/console 7.x
-          composer-options: ${{ matrix.composer-version != '2.7' && '--with symfony/console:<7' }}
+          composer-options: ${{ matrix.composer-version != '2.7' && '--with symfony/console:<7' || '' }}
 
       # Run tests
       - name: Run tests
diff --git a/src/Builder/BuildInstructions.php b/src/Builder/BuildInstructions.php
index 0bb85e88..108c665a 100644
--- a/src/Builder/BuildInstructions.php
+++ b/src/Builder/BuildInstructions.php
@@ -26,7 +26,6 @@
 use ArrayObject;
 use CPSIT\ProjectBuilder\Helper;
 use CPSIT\ProjectBuilder\Paths;
-use Symfony\Component\Filesystem;
 
 use function dirname;
 
@@ -62,12 +61,12 @@ public function getTemplateDirectory(): string
 
     public function getSourceDirectory(): string
     {
-        return Filesystem\Path::join($this->getTemplateDirectory(), Paths::TEMPLATE_SOURCES);
+        return Helper\FilesystemHelper::path($this->getTemplateDirectory(), Paths::TEMPLATE_SOURCES);
     }
 
     public function getSharedSourceDirectory(): string
     {
-        return Filesystem\Path::join($this->getTemplateDirectory(), Paths::TEMPLATE_SHARED_SOURCES);
+        return Helper\FilesystemHelper::path($this->getTemplateDirectory(), Paths::TEMPLATE_SHARED_SOURCES);
     }
 
     public function getTemporaryDirectory(): string
diff --git a/src/Builder/Config/ConfigFactory.php b/src/Builder/Config/ConfigFactory.php
index 93883dad..be8233c9 100644
--- a/src/Builder/Config/ConfigFactory.php
+++ b/src/Builder/Config/ConfigFactory.php
@@ -99,8 +99,7 @@ public function buildFromString(string $content, string $identifier, FileType $f
 
     private function validateConfig(stdClass $parsedContent): JsonSchema\ValidationResult
     {
-        $schemaFile = Filesystem\Path::join(Helper\FilesystemHelper::getProjectRootPath(), Paths::PROJECT_SCHEMA_CONFIG);
-        $schemaReference = 'file://'.$schemaFile;
+        $schemaFile = Helper\FilesystemHelper::path(Helper\FilesystemHelper::getProjectRootPath(), Paths::PROJECT_SCHEMA_CONFIG);
         $schemaResolver = $this->validator->resolver();
 
         // @codeCoverageIgnoreStart
@@ -110,9 +109,9 @@ private function validateConfig(stdClass $parsedContent): JsonSchema\ValidationR
         }
         // @codeCoverageIgnoreEnd
 
-        $schemaResolver->registerFile($schemaReference, $schemaFile);
+        $schemaResolver->registerFile(Paths::PROJECT_SCHEMA_REFERENCE, $schemaFile);
 
-        return $this->validator->validate($parsedContent, $schemaReference);
+        return $this->validator->validate($parsedContent, Paths::PROJECT_SCHEMA_REFERENCE);
     }
 
     private function generateMapperSource(string $content, string $identifier, FileType $fileType): Mapper\Source\Source
diff --git a/src/Builder/Config/ConfigReader.php b/src/Builder/Config/ConfigReader.php
index e2a9374a..12c439eb 100644
--- a/src/Builder/Config/ConfigReader.php
+++ b/src/Builder/Config/ConfigReader.php
@@ -65,7 +65,7 @@ private function __construct(
 
     public static function create(?string $templateDirectory = null): self
     {
-        $templateDirectory ??= Filesystem\Path::join(Helper\FilesystemHelper::getProjectRootPath(), Paths::PROJECT_TEMPLATES);
+        $templateDirectory ??= Helper\FilesystemHelper::path(Helper\FilesystemHelper::getProjectRootPath(), Paths::PROJECT_TEMPLATES);
 
         return new self(ConfigFactory::create(), $templateDirectory);
     }
diff --git a/src/Builder/Generator/Step/InstallComposerDependenciesStep.php b/src/Builder/Generator/Step/InstallComposerDependenciesStep.php
index fd9e0621..ba4cef6d 100644
--- a/src/Builder/Generator/Step/InstallComposerDependenciesStep.php
+++ b/src/Builder/Generator/Step/InstallComposerDependenciesStep.php
@@ -25,10 +25,10 @@
 
 use Composer\IO as ComposerIO;
 use CPSIT\ProjectBuilder\Builder;
+use CPSIT\ProjectBuilder\Helper;
 use CPSIT\ProjectBuilder\IO;
 use CPSIT\ProjectBuilder\Resource;
 use Symfony\Component\Console;
-use Symfony\Component\Filesystem;
 
 /**
  * InstallComposerDependenciesStep.
@@ -49,7 +49,7 @@ public function __construct(
 
     public function run(Builder\BuildResult $buildResult): bool
     {
-        $composerJson = Filesystem\Path::join($buildResult->getInstructions()->getTemplateDirectory(), 'composer.json');
+        $composerJson = Helper\FilesystemHelper::path($buildResult->getInstructions()->getTemplateDirectory(), 'composer.json');
         $exitCode = $this->runComposerInstall($composerJson);
 
         $buildResult->applyStep($this);
diff --git a/src/Builder/Generator/Step/ProcessSharedSourceFilesStep.php b/src/Builder/Generator/Step/ProcessSharedSourceFilesStep.php
index d229be3e..0d415c77 100644
--- a/src/Builder/Generator/Step/ProcessSharedSourceFilesStep.php
+++ b/src/Builder/Generator/Step/ProcessSharedSourceFilesStep.php
@@ -24,6 +24,7 @@
 namespace CPSIT\ProjectBuilder\Builder\Generator\Step;
 
 use CPSIT\ProjectBuilder\Builder;
+use CPSIT\ProjectBuilder\Helper;
 use CPSIT\ProjectBuilder\IO;
 use CPSIT\ProjectBuilder\Paths;
 use CPSIT\ProjectBuilder\Resource;
@@ -95,7 +96,7 @@ public static function supports(string $type): bool
 
     private function listSharedSourceFiles(Builder\BuildInstructions $instructions): Finder\Finder
     {
-        $basePath = Filesystem\Path::join(
+        $basePath = Helper\FilesystemHelper::path(
             $instructions->getSharedSourceDirectory(),
             // Include all installed shared source packages
             '*',
diff --git a/src/Console/Application.php b/src/Console/Application.php
index 39d8ce1a..0a5cc703 100644
--- a/src/Console/Application.php
+++ b/src/Console/Application.php
@@ -27,6 +27,7 @@
 use CPSIT\ProjectBuilder\DependencyInjection;
 use CPSIT\ProjectBuilder\Error;
 use CPSIT\ProjectBuilder\Exception;
+use CPSIT\ProjectBuilder\Helper;
 use CPSIT\ProjectBuilder\IO;
 use CPSIT\ProjectBuilder\Paths;
 use CPSIT\ProjectBuilder\Resource;
@@ -127,8 +128,8 @@ public function run(bool $disableTemplateSourceCache = false): int
     private function mirrorSourceFiles(): void
     {
         $this->filesystem->mirror(
-            Filesystem\Path::join($this->targetDirectory, Paths::PROJECT_SOURCES),
-            Filesystem\Path::join($this->targetDirectory, '.build', Paths::PROJECT_SOURCES),
+            Helper\FilesystemHelper::path($this->targetDirectory, Paths::PROJECT_SOURCES),
+            Helper\FilesystemHelper::path($this->targetDirectory, '.build', Paths::PROJECT_SOURCES),
         );
     }
 
diff --git a/src/Console/Simulation.php b/src/Console/Simulation.php
index f1f8a220..31b9c082 100644
--- a/src/Console/Simulation.php
+++ b/src/Console/Simulation.php
@@ -65,7 +65,7 @@ public static function create(): self
             new Resource\Local\Composer($filesystem),
             Factory::createOutput(),
             $rootPath,
-            Filesystem\Path::join($rootPath, '.build', uniqid('simulate_')),
+            Helper\FilesystemHelper::path($rootPath, '.build', uniqid('simulate_')),
         );
     }
 
@@ -88,7 +88,7 @@ public function prepare(): string
 
         // Install project
         $exitCode = $this->composer->install(
-            Filesystem\Path::join($this->targetDirectory, 'composer.json'),
+            Helper\FilesystemHelper::path($this->targetDirectory, 'composer.json'),
             true,
             $this->output,
         );
diff --git a/src/DependencyInjection/ContainerFactory.php b/src/DependencyInjection/ContainerFactory.php
index fe918e51..ffdaa583 100644
--- a/src/DependencyInjection/ContainerFactory.php
+++ b/src/DependencyInjection/ContainerFactory.php
@@ -71,7 +71,7 @@ public static function create(array $resourcePaths = []): self
     public static function createFromConfig(Builder\Config\Config $config): self
     {
         $resourcePaths = [
-            Filesystem\Path::join(
+            Helper\FilesystemHelper::path(
                 Helper\FilesystemHelper::getProjectRootPath(),
                 Paths::PROJECT_TEMPLATES,
                 basename(dirname($config->getDeclaringFile())),
@@ -85,22 +85,20 @@ public static function createFromConfig(Builder\Config\Config $config): self
     public static function createForTesting(string $testsRootPath = 'tests'): self
     {
         if (!Filesystem\Path::isAbsolute($testsRootPath)) {
-            $testsRootPath = Filesystem\Path::join(
+            $testsRootPath = Helper\FilesystemHelper::path(
                 Helper\FilesystemHelper::getProjectRootPath(),
                 $testsRootPath,
             );
         }
         $resources = self::locateResources([
-            Filesystem\Path::join(
+            Helper\FilesystemHelper::path(
                 $testsRootPath,
                 'config',
             ),
         ]);
-        $containerPath = Filesystem\Path::join(
+        $containerPath = Helper\FilesystemHelper::path(
             Helper\FilesystemHelper::getProjectRootPath(),
-            'var',
-            'cache',
-            'test-container.php',
+            'var/cache/test-container.php',
         );
 
         $filesystem = new Filesystem\Filesystem();
@@ -115,7 +113,7 @@ public function get(): DependencyInjection\ContainerInterface
 
         if ($this->debug && null !== $this->containerPath) {
             $containerXmlFilename = Filesystem\Path::getFilenameWithoutExtension($this->containerPath);
-            $containerXmlPath = Filesystem\Path::join(dirname($this->containerPath), $containerXmlFilename.'.xml');
+            $containerXmlPath = Helper\FilesystemHelper::path(dirname($this->containerPath), $containerXmlFilename.'.xml');
             $container->addCompilerPass(new CompilerPass\ContainerBuilderDebugDumpPass($containerXmlPath));
         }
 
@@ -185,6 +183,6 @@ private static function locateResources(array $resourcePaths = []): array
 
     private static function getDefaultResourcePath(): string
     {
-        return Filesystem\Path::join(Helper\FilesystemHelper::getProjectRootPath(), Paths::PROJECT_SERVICE_CONFIG);
+        return Helper\FilesystemHelper::path(Helper\FilesystemHelper::getProjectRootPath(), Paths::PROJECT_SERVICE_CONFIG);
     }
 }
diff --git a/src/Helper/FilesystemHelper.php b/src/Helper/FilesystemHelper.php
index c3faca52..79e058d1 100644
--- a/src/Helper/FilesystemHelper.php
+++ b/src/Helper/FilesystemHelper.php
@@ -28,7 +28,9 @@
 use Symfony\Component\Finder;
 
 use function dirname;
+use function explode;
 use function getenv;
+use function implode;
 
 /**
  * FilesystemHelper.
@@ -41,7 +43,7 @@ final class FilesystemHelper
     public static function createFileObject(string $baseDir, string $relativePathname): Finder\SplFileInfo
     {
         return new Finder\SplFileInfo(
-            Filesystem\Path::join($baseDir, $relativePathname),
+            self::path($baseDir, $relativePathname),
             dirname($relativePathname),
             $relativePathname,
         );
@@ -50,7 +52,7 @@ public static function createFileObject(string $baseDir, string $relativePathnam
     public static function getNewTemporaryDirectory(): string
     {
         do {
-            $dir = Filesystem\Path::join(sys_get_temp_dir(), uniqid('cpsit_project_builder_'));
+            $dir = self::path(sys_get_temp_dir(), uniqid('cpsit_project_builder_'));
         } while (is_dir($dir));
 
         return $dir;
@@ -63,9 +65,16 @@ public static function getProjectRootPath(): string
         }
 
         if (null !== $rootPath) {
-            $rootPath = Filesystem\Path::canonicalize($rootPath);
+            $rootPath = self::path($rootPath);
         }
 
         return $rootPath ?? dirname(__DIR__, 2);
     }
+
+    public static function path(string ...$segments): string
+    {
+        $normalizedSegments = explode('/', Filesystem\Path::join(...$segments));
+
+        return implode(DIRECTORY_SEPARATOR, $normalizedSegments);
+    }
 }
diff --git a/src/Paths.php b/src/Paths.php
index e3bc3235..658c346b 100644
--- a/src/Paths.php
+++ b/src/Paths.php
@@ -48,6 +48,11 @@ enum Paths
      */
     final public const PROJECT_SCHEMA_CONFIG = 'resources/config.schema.json';
 
+    /**
+     * Internal reference to the JSON schema for template config files.
+     */
+    final public const PROJECT_SCHEMA_REFERENCE = 'https://project-builder.cps-it.de/schema.json';
+
     /**
      * Path to service configurations.
      */
diff --git a/src/Resource/Local/Composer.php b/src/Resource/Local/Composer.php
index 79790b7c..40f508fd 100644
--- a/src/Resource/Local/Composer.php
+++ b/src/Resource/Local/Composer.php
@@ -136,7 +136,7 @@ public static function createComposer(string $rootPath): \Composer\Composer
 
         return $factory->createComposer(
             new IO\NullIO(),
-            Filesystem\Path::join($rootPath, 'composer.json'),
+            Helper\FilesystemHelper::path($rootPath, 'composer.json'),
         );
     }
 }
diff --git a/src/Template/Provider/BaseProvider.php b/src/Template/Provider/BaseProvider.php
index 57464917..0d27b211 100644
--- a/src/Template/Provider/BaseProvider.php
+++ b/src/Template/Provider/BaseProvider.php
@@ -66,7 +66,7 @@ public function __construct(
         $this->composer = new Resource\Local\Composer($this->filesystem);
         $this->renderer = new Environment(
             new Loader\FilesystemLoader([
-                Filesystem\Path::join(
+                Helper\FilesystemHelper::path(
                     Helper\FilesystemHelper::getProjectRootPath(),
                     Paths::PROJECT_INSTALLER,
                 ),
@@ -272,7 +272,7 @@ protected function createComposerJson(array $templateSources, array $repositorie
         ];
 
         $targetDirectory = Helper\FilesystemHelper::getNewTemporaryDirectory();
-        $targetFile = Filesystem\Path::join($targetDirectory, 'composer.json');
+        $targetFile = Helper\FilesystemHelper::path($targetDirectory, 'composer.json');
         $composerJson = $this->renderer->render('composer.json.twig', [
             'templateSources' => $templateSources,
             'rootDir' => Helper\FilesystemHelper::getProjectRootPath(),
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index c1d836af..5c71cecd 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -21,6 +21,14 @@
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
 
+// Assure cross-platform compatible line break is used in tests
+if (!defined('LF')) {
+    define('LF', match (PHP_OS) {
+        'Windows' => "\r\n",
+        default => "\n",
+    });
+}
+
 require_once dirname(__DIR__).'/.build/vendor/autoload.php';
 
 $factory = CPSIT\ProjectBuilder\DependencyInjection\ContainerFactory::createForTesting();
diff --git a/tests/src/Builder/BuildInstructionsTest.php b/tests/src/Builder/BuildInstructionsTest.php
index 35b8dc19..075b0020 100644
--- a/tests/src/Builder/BuildInstructionsTest.php
+++ b/tests/src/Builder/BuildInstructionsTest.php
@@ -63,13 +63,19 @@ public function getTemplateDirectoryReturnsTemplateDirectory(): void
     #[Framework\Attributes\Test]
     public function getSourceDirectoryReturnsSourceDirectory(): void
     {
-        self::assertSame(dirname(__DIR__).'/templates/src', $this->subject->getSourceDirectory());
+        self::assertSame(
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__), 'templates/src'),
+            $this->subject->getSourceDirectory(),
+        );
     }
 
     #[Framework\Attributes\Test]
     public function getSharedSourceDirectoryReturnsSharedSourceDirectory(): void
     {
-        self::assertSame(dirname(__DIR__).'/templates/shared', $this->subject->getSharedSourceDirectory());
+        self::assertSame(
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__), 'templates/shared'),
+            $this->subject->getSharedSourceDirectory(),
+        );
     }
 
     #[Framework\Attributes\Test]
diff --git a/tests/src/Builder/Config/ConfigFactoryTest.php b/tests/src/Builder/Config/ConfigFactoryTest.php
index 47e18c6a..1a1b5f42 100644
--- a/tests/src/Builder/Config/ConfigFactoryTest.php
+++ b/tests/src/Builder/Config/ConfigFactoryTest.php
@@ -136,7 +136,7 @@ public function buildFromFileReturnsHydratedConfigObject(): void
         );
 
         foreach (['json', 'yaml'] as $fileType) {
-            $configFile = dirname(__DIR__, 2).'/Fixtures/Templates/'.$fileType.'-template/config.'.$fileType;
+            $configFile = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Templates/'.$fileType.'-template/config.'.$fileType);
             $expected = $createConfig($fileType);
             $expected->setDeclaringFile($configFile);
 
@@ -159,10 +159,16 @@ public function buildFromStringThrowsExceptionIfGivenContentIsInvalid(): void
      */
     public static function buildFromFileThrowsExceptionIfFileContentsAreInvalidDataProvider(): Generator
     {
-        $fixturePath = dirname(__DIR__, 2).'/Fixtures/Files';
-
-        yield 'invalid file' => [$fixturePath.'/invalid-config-file.yaml'];
-        yield 'invalid path at file condition' => [$fixturePath.'/invalid-config-file-condition-path.yaml'];
-        yield 'invalid target at file condition' => [$fixturePath.'/invalid-config-file-condition-target.yaml'];
+        $fixturePath = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Files');
+
+        yield 'invalid file' => [
+            Src\Helper\FilesystemHelper::path($fixturePath, 'invalid-config-file.yaml'),
+        ];
+        yield 'invalid path at file condition' => [
+            Src\Helper\FilesystemHelper::path($fixturePath, 'invalid-config-file-condition-path.yaml'),
+        ];
+        yield 'invalid target at file condition' => [
+            Src\Helper\FilesystemHelper::path($fixturePath, 'invalid-config-file-condition-target.yaml'),
+        ];
     }
 }
diff --git a/tests/src/Builder/Config/ConfigReaderTest.php b/tests/src/Builder/Config/ConfigReaderTest.php
index 17694f1c..b2da6da5 100644
--- a/tests/src/Builder/Config/ConfigReaderTest.php
+++ b/tests/src/Builder/Config/ConfigReaderTest.php
@@ -41,7 +41,7 @@ final class ConfigReaderTest extends Framework\TestCase
     protected function setUp(): void
     {
         $this->subject = Src\Builder\Config\ConfigReader::create(
-            dirname(__DIR__, 2).'/Fixtures/Templates',
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Templates'),
         );
     }
 
@@ -60,11 +60,13 @@ public function createCreatesTemplateDirectoryIfItDoesNotExist(): void
     #[Framework\Attributes\Test]
     public function readConfigThrowsExceptionIfTemplateHasNoComposerJson(): void
     {
-        $templateDirectory = dirname(__DIR__, 2).'/Fixtures';
+        $templateDirectory = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures');
         $subject = Src\Builder\Config\ConfigReader::create($templateDirectory);
 
         $this->expectExceptionObject(
-            Src\Exception\InvalidConfigurationException::forMissingManifestFile($templateDirectory.'/Files/config.json'),
+            Src\Exception\InvalidConfigurationException::forMissingManifestFile(
+                Src\Helper\FilesystemHelper::path($templateDirectory, 'Files/config.json'),
+            ),
         );
 
         $subject->readConfig('foo');
@@ -84,7 +86,7 @@ public function readConfigThrowsExceptionIfTemplateWithGivenIdentifierDoesNotExi
     public function readConfigThrowsExceptionIfTemplateContainsMultipleConfigFiles(): void
     {
         $subject = Src\Builder\Config\ConfigReader::create(
-            dirname(__DIR__, 2).'/Fixtures/Files',
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Files'),
         );
 
         $this->expectException(Src\Exception\InvalidConfigurationException::class);
@@ -101,7 +103,7 @@ public function readConfigReturnsHydratedConfigObject(): void
 
         self::assertSame('cpsit/project-builder-template-yaml', $actual->getIdentifier());
         self::assertSame(
-            dirname(__DIR__, 2).'/Fixtures/Templates/yaml-template/config.yaml',
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Templates/yaml-template/config.yaml'),
             $actual->getDeclaringFile(),
         );
     }
diff --git a/tests/src/Builder/Generator/GeneratorTest.php b/tests/src/Builder/Generator/GeneratorTest.php
index 0162b353..32583661 100644
--- a/tests/src/Builder/Generator/GeneratorTest.php
+++ b/tests/src/Builder/Generator/GeneratorTest.php
@@ -77,8 +77,11 @@ public function runRunsThroughAllConfiguredSteps(): void
         self::assertStringContainsString('Running step #5 "mirrorProcessedFiles"...', $output);
         self::assertStringContainsString('Running step #6 "runCommand"...', $output);
 
-        self::assertFileExists($this->targetDirectory.'/dummy.yaml');
-        self::assertStringEqualsFile($this->targetDirectory.'/dummy.yaml', 'name: "foo"'.PHP_EOL);
+        self::assertFileExists(Src\Helper\FilesystemHelper::path($this->targetDirectory, 'dummy.yaml'));
+        self::assertStringEqualsFile(
+            Src\Helper\FilesystemHelper::path($this->targetDirectory, 'dummy.yaml'),
+            'name: "foo"'.LF,
+        );
 
         self::assertCount(9, $this->eventListener->dispatchedEvents);
         self::assertInstanceOf(Src\Event\ProjectBuildStartedEvent::class, $this->eventListener->dispatchedEvents[0]);
@@ -109,8 +112,11 @@ public function runRestartsProjectGenerationOnStepFailure(): void
         $output = self::$io->getOutput();
 
         self::assertStringContainsString('If you want, you can restart project generation now.', $output);
-        self::assertFileExists($this->targetDirectory.'/dummy.yaml');
-        self::assertStringEqualsFile($this->targetDirectory.'/dummy.yaml', 'name: "foo"'.PHP_EOL);
+        self::assertFileExists(Src\Helper\FilesystemHelper::path($this->targetDirectory, 'dummy.yaml'));
+        self::assertStringEqualsFile(
+            Src\Helper\FilesystemHelper::path($this->targetDirectory, 'dummy.yaml'),
+            'name: "foo"'.LF,
+        );
 
         self::assertCount(12, $this->eventListener->dispatchedEvents);
         self::assertInstanceOf(Src\Event\ProjectBuildStartedEvent::class, $this->eventListener->dispatchedEvents[0]);
@@ -202,7 +208,7 @@ public function runDisplaysExceptionTraceOnVeryVerboseOutput(): void
         }
 
         self::assertStringContainsString(
-            'Exception: The given input must not be empty.'.PHP_EOL.'#0',
+            'Exception: The given input must not be empty.'.LF.'#0',
             self::$io->getOutput(),
         );
     }
@@ -236,7 +242,7 @@ protected static function createConfig(): Src\Builder\Config\Config
         $configReader = Src\Builder\Config\ConfigFactory::create();
 
         $config = $configReader->buildFromFile(
-            dirname(__DIR__, 2).'/Fixtures/Templates/yaml-template/config.yaml',
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Templates/yaml-template/config.yaml'),
             'yaml',
         );
         $config->setTemplateSource(
diff --git a/tests/src/Builder/Generator/Step/CleanUpStepTest.php b/tests/src/Builder/Generator/Step/CleanUpStepTest.php
index ce19b0e2..f81ff4fa 100644
--- a/tests/src/Builder/Generator/Step/CleanUpStepTest.php
+++ b/tests/src/Builder/Generator/Step/CleanUpStepTest.php
@@ -58,16 +58,16 @@ public function runCleansUpRemainingFilesInTargetDirectory(): void
     {
         $targetDirectory = $this->result->getInstructions()->getTargetDirectory();
 
-        $this->filesystem->mkdir($targetDirectory.'/.build');
-        $this->filesystem->touch($targetDirectory.'/foo');
+        $this->filesystem->mkdir(Src\Helper\FilesystemHelper::path($targetDirectory, '.build'));
+        $this->filesystem->touch(Src\Helper\FilesystemHelper::path($targetDirectory, 'foo'));
 
-        self::assertDirectoryExists($targetDirectory.'/.build');
-        self::assertFileExists($targetDirectory.'/foo');
+        self::assertDirectoryExists(Src\Helper\FilesystemHelper::path($targetDirectory, '.build'));
+        self::assertFileExists(Src\Helper\FilesystemHelper::path($targetDirectory, 'foo'));
 
         $this->subject->run($this->result);
 
-        self::assertDirectoryDoesNotExist($targetDirectory.'/.build');
-        self::assertFileExists($targetDirectory.'/foo');
+        self::assertDirectoryDoesNotExist(Src\Helper\FilesystemHelper::path($targetDirectory, '.build'));
+        self::assertFileExists(Src\Helper\FilesystemHelper::path($targetDirectory, 'foo'));
         self::assertTrue($this->result->isStepApplied('cleanUp'));
     }
 
diff --git a/tests/src/Builder/Generator/Step/GenerateBuildArtifactStepTest.php b/tests/src/Builder/Generator/Step/GenerateBuildArtifactStepTest.php
index 8edb41b8..20cfd141 100644
--- a/tests/src/Builder/Generator/Step/GenerateBuildArtifactStepTest.php
+++ b/tests/src/Builder/Generator/Step/GenerateBuildArtifactStepTest.php
@@ -49,7 +49,7 @@ protected function setUp(): void
         $this->buildResult = new Src\Builder\BuildResult(
             new Src\Builder\BuildInstructions(self::$config, 'foo'),
         );
-        $this->artifactPath = Filesystem\Path::join(
+        $this->artifactPath = Src\Helper\FilesystemHelper::path(
             $this->buildResult->getWrittenDirectory(),
             '.build/build-artifact.json',
         );
diff --git a/tests/src/Builder/Generator/Step/InstallComposerDependenciesStepTest.php b/tests/src/Builder/Generator/Step/InstallComposerDependenciesStepTest.php
index ccd50f7e..d1e2b2ba 100644
--- a/tests/src/Builder/Generator/Step/InstallComposerDependenciesStepTest.php
+++ b/tests/src/Builder/Generator/Step/InstallComposerDependenciesStepTest.php
@@ -67,8 +67,8 @@ public function runWritesComposerInstallOutputAndFailsOnFailure(): void
 
         self::$config->setDeclaringFile($newConfig->getDeclaringFile());
         self::$filesystem->copy(
-            dirname(__DIR__, 3).'/Fixtures/Files/invalid-composer.json',
-            self::$temporaryDirectory.'/composer.json',
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'Fixtures/Files/invalid-composer.json'),
+            Src\Helper\FilesystemHelper::path(self::$temporaryDirectory, 'composer.json'),
             true,
         );
 
@@ -81,7 +81,7 @@ public function runWritesComposerInstallOutputAndFailsOnFailure(): void
 
     protected static function createConfig(): Src\Builder\Config\Config
     {
-        $templateDirectory = dirname(__DIR__, 3).'/Fixtures/Templates/yaml-template';
+        $templateDirectory = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'Fixtures/Templates/yaml-template');
         $finder = Finder\Finder::create()
             ->in($templateDirectory)
             ->notPath('vendor')
@@ -94,7 +94,10 @@ protected static function createConfig(): Src\Builder\Config\Config
 
         $configFactory = Src\Builder\Config\ConfigFactory::create();
 
-        return $configFactory->buildFromFile(self::$temporaryDirectory.'/config.yaml', 'yaml');
+        return $configFactory->buildFromFile(
+            Src\Helper\FilesystemHelper::path(self::$temporaryDirectory, 'config.yaml'),
+            'yaml',
+        );
     }
 
     protected function tearDown(): void
diff --git a/tests/src/Builder/Generator/Step/ProcessSharedSourceFilesStepTest.php b/tests/src/Builder/Generator/Step/ProcessSharedSourceFilesStepTest.php
index 8dcc8cff..8895d8fa 100644
--- a/tests/src/Builder/Generator/Step/ProcessSharedSourceFilesStepTest.php
+++ b/tests/src/Builder/Generator/Step/ProcessSharedSourceFilesStepTest.php
@@ -56,17 +56,36 @@ public function runProcessesSourceFilesAndAppliesStep(): void
 
         $actual = $this->subject->run($this->result);
 
+        $temporaryDirectory = $this->result->getInstructions()->getTemporaryDirectory();
+
         self::assertTrue($actual);
         self::assertCount(4, $this->subject->getProcessedFiles());
-        self::assertSame('overrides/shared-dummy-4.yaml', $this->subject->getProcessedFiles()[0]->getTargetFile()->getRelativePathname());
+        self::assertSame(
+            'overrides/shared-dummy-4.yaml',
+            $this->subject->getProcessedFiles()[0]->getTargetFile()->getRelativePathname(),
+        );
         self::assertSame('shared-dummy.yaml', $this->subject->getProcessedFiles()[1]->getTargetFile()->getRelativePathname());
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/shared-dummy.yaml');
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/shared-dummy-2.yaml');
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/shared-dummy-3.yaml');
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/shared-dummy-4.yaml');
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/overrides/shared-dummy-4.yaml');
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/foo-baz-shared-dummy/shared-dummy-1.yaml');
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/foo-baz-shared-dummy/shared-dummy-2.yaml');
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory, 'shared-dummy.yaml'),
+        );
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory, 'shared-dummy-2.yaml'),
+        );
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory, 'shared-dummy-3.yaml'),
+        );
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory, 'shared-dummy-4.yaml'),
+        );
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory, 'overrides/shared-dummy-4.yaml'),
+        );
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory, 'foo-baz-shared-dummy/shared-dummy-1.yaml'),
+        );
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory, 'foo-baz-shared-dummy/shared-dummy-2.yaml'),
+        );
         self::assertTrue($this->result->isStepApplied($this->subject));
     }
 
@@ -75,11 +94,15 @@ public function revertRemovesProcessedFiles(): void
     {
         $this->subject->run($this->result);
 
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/shared-dummy.yaml');
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($this->result->getInstructions()->getTemporaryDirectory(), 'shared-dummy.yaml'),
+        );
 
         $this->subject->revert($this->result);
 
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/shared-dummy.yaml');
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($this->result->getInstructions()->getTemporaryDirectory(), 'shared-dummy.yaml'),
+        );
     }
 
     protected static function createConfig(): Src\Builder\Config\Config
@@ -87,7 +110,7 @@ protected static function createConfig(): Src\Builder\Config\Config
         $configFactory = Src\Builder\Config\ConfigFactory::create();
 
         return $configFactory->buildFromFile(
-            dirname(__DIR__, 3).'/Fixtures/Templates/yaml-template/config.yaml',
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'Fixtures/Templates/yaml-template/config.yaml'),
             'yaml',
         );
     }
diff --git a/tests/src/Builder/Generator/Step/ProcessSourceFilesStepTest.php b/tests/src/Builder/Generator/Step/ProcessSourceFilesStepTest.php
index b4a543d0..e5e54ab6 100644
--- a/tests/src/Builder/Generator/Step/ProcessSourceFilesStepTest.php
+++ b/tests/src/Builder/Generator/Step/ProcessSourceFilesStepTest.php
@@ -59,17 +59,36 @@ public function runProcessesSourceFilesAndAppliesStep(): void
 
         $actual = $this->subject->run($this->result);
 
+        $temporaryDirectory = $this->result->getInstructions()->getTemporaryDirectory();
+
         self::assertTrue($actual);
         self::assertCount(4, $this->subject->getProcessedFiles());
-        self::assertSame('overrides/dummy-4.yaml', $this->subject->getProcessedFiles()[0]->getTargetFile()->getRelativePathname());
+        self::assertSame(
+            'overrides/dummy-4.yaml',
+            $this->subject->getProcessedFiles()[0]->getTargetFile()->getRelativePathname(),
+        );
         self::assertSame('dummy.yaml', $this->subject->getProcessedFiles()[1]->getTargetFile()->getRelativePathname());
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/dummy.yaml');
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/dummy-2.yaml');
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/dummy-3.yaml');
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/dummy-4.yaml');
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/overrides/dummy-4.yaml');
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/foo-baz-dummy/dummy-1.yaml');
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/foo-baz-dummy/dummy-2.yaml');
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory.'/dummy.yaml'),
+        );
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory.'/dummy-2.yaml'),
+        );
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory.'/dummy-3.yaml'),
+        );
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory.'/dummy-4.yaml'),
+        );
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory.'/overrides/dummy-4.yaml'),
+        );
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory.'/foo-baz-dummy/dummy-1.yaml'),
+        );
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($temporaryDirectory.'/foo-baz-dummy/dummy-2.yaml'),
+        );
         self::assertTrue($this->result->isStepApplied($this->subject));
     }
 
@@ -84,7 +103,7 @@ public function runCanProcessTheSameSourceFileWithMultipleConditions(
         string $expected,
         array $notExpected,
     ): void {
-        $declaringFile = dirname(__DIR__, 3).'/Fixtures/Templates/yaml-template/config.yaml';
+        $declaringFile = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'Fixtures/Templates/yaml-template/config.yaml');
         $step = new Src\Builder\Config\ValueObject\Step(
             'processSourceFiles',
             new Src\Builder\Config\ValueObject\StepOptions($fileConditions),
@@ -100,10 +119,14 @@ public function runCanProcessTheSameSourceFileWithMultipleConditions(
 
         $this->subject->run($result);
 
-        self::assertFileExists($result->getInstructions()->getTemporaryDirectory().'/'.$expected);
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($result->getInstructions()->getTemporaryDirectory(), $expected),
+        );
 
         foreach ($notExpected as $notExpectedFile) {
-            self::assertFileDoesNotExist($result->getInstructions()->getTemporaryDirectory().'/'.$notExpectedFile);
+            self::assertFileDoesNotExist(
+                Src\Helper\FilesystemHelper::path($result->getInstructions()->getTemporaryDirectory(), $notExpectedFile),
+            );
         }
     }
 
@@ -112,11 +135,15 @@ public function revertRemovesProcessedFiles(): void
     {
         $this->subject->run($this->result);
 
-        self::assertFileExists($this->result->getInstructions()->getTemporaryDirectory().'/dummy.yaml');
+        self::assertFileExists(
+            Src\Helper\FilesystemHelper::path($this->result->getInstructions()->getTemporaryDirectory(), 'dummy.yaml'),
+        );
 
         $this->subject->revert($this->result);
 
-        self::assertFileDoesNotExist($this->result->getInstructions()->getTemporaryDirectory().'/dummy.yaml');
+        self::assertFileDoesNotExist(
+            Src\Helper\FilesystemHelper::path($this->result->getInstructions()->getTemporaryDirectory(), 'dummy.yaml'),
+        );
     }
 
     /**
@@ -167,7 +194,7 @@ protected static function createConfig(): Src\Builder\Config\Config
         $configFactory = Src\Builder\Config\ConfigFactory::create();
 
         return $configFactory->buildFromFile(
-            dirname(__DIR__, 3).'/Fixtures/Templates/yaml-template/config.yaml',
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'Fixtures/Templates/yaml-template/config.yaml'),
             'yaml',
         );
     }
diff --git a/tests/src/Builder/Generator/Step/RunCommandStepTest.php b/tests/src/Builder/Generator/Step/RunCommandStepTest.php
index d3cc3fca..84b378f7 100644
--- a/tests/src/Builder/Generator/Step/RunCommandStepTest.php
+++ b/tests/src/Builder/Generator/Step/RunCommandStepTest.php
@@ -121,9 +121,15 @@ public function runExecutesCommandAndAllowsExecutionFailures(): void
             $fileSystem->mkdir($workingDirectory);
         }
 
+        if (PHP_OS_FAMILY === 'Windows') {
+            $expected = 'is not recognized as an internal or external command';
+        } else {
+            $expected = 'not found';
+        }
+
         self::assertTrue($this->subject->run($this->result));
         self::assertFalse($this->subject->isStopped());
-        self::assertStringContainsString('not found', self::$io->getOutput());
+        self::assertStringContainsString($expected, self::$io->getOutput());
     }
 
     #[Framework\Attributes\Test]
diff --git a/tests/src/Builder/Generator/Step/ShowNextStepsStepTest.php b/tests/src/Builder/Generator/Step/ShowNextStepsStepTest.php
index 6b0fbc27..6ed071a2 100644
--- a/tests/src/Builder/Generator/Step/ShowNextStepsStepTest.php
+++ b/tests/src/Builder/Generator/Step/ShowNextStepsStepTest.php
@@ -83,7 +83,7 @@ public function runThrowsExceptionIfTemplateFileCannotBeRendered(): void
                 Src\Builder\Generator\Step\ShowNextStepsStep::getType(),
                 new Src\Builder\Config\ValueObject\StepOptions(
                     [],
-                    dirname(__DIR__, 3).'/Fixtures/Files/invalid-template.twig',
+                    Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'Fixtures/Files/invalid-template.twig'),
                 ),
             ),
         );
@@ -103,7 +103,7 @@ public function runShowsNextStepsFromRenderedTemplateFileAndAppliesStep(): void
                 Src\Builder\Generator\Step\ShowNextStepsStep::getType(),
                 new Src\Builder\Config\ValueObject\StepOptions(
                     [],
-                    dirname(__DIR__, 3).'/Fixtures/Templates/yaml-template/templates/next-steps.html.twig',
+                    Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'Fixtures/Templates/yaml-template/templates/next-steps.html.twig'),
                 ),
             ),
         );
@@ -113,7 +113,7 @@ public function runShowsNextStepsFromRenderedTemplateFileAndAppliesStep(): void
 
         self::assertTrue($actual);
         self::assertStringContainsString('Next steps', $output);
-        self::assertStringContainsString('Hello'.PHP_EOL.'World', $output);
+        self::assertStringContainsString('Hello'.LF.'World', $output);
         self::assertTrue($this->result->isStepApplied($this->subject));
     }
 }
diff --git a/tests/src/Builder/Writer/GenericFileWriterTest.php b/tests/src/Builder/Writer/GenericFileWriterTest.php
index 97135d65..b64ea60f 100644
--- a/tests/src/Builder/Writer/GenericFileWriterTest.php
+++ b/tests/src/Builder/Writer/GenericFileWriterTest.php
@@ -57,7 +57,7 @@ public function writeCopiesGivenFileToTemporaryDirectory(): void
         $sourceFile = __FILE__;
         $file = new Finder\SplFileInfo($sourceFile, dirname($sourceFile), basename($sourceFile));
 
-        $expected = $instructions->getTemporaryDirectory().'/'.$file->getRelativePathname();
+        $expected = Src\Helper\FilesystemHelper::path($instructions->getTemporaryDirectory(), $file->getRelativePathname());
         $actual = $this->subject->write($instructions, $file);
 
         self::assertSame($expected, $actual->getPathname());
@@ -76,8 +76,8 @@ public function writeCopiesGivenFileToGivenTargetFile(): void
         $sourceFile = __FILE__;
         $file = new Finder\SplFileInfo($sourceFile, dirname($sourceFile), basename($sourceFile));
 
-        $expected = $instructions->getTemporaryDirectory().'/overrides/foo.php';
-        $actual = $this->subject->write($instructions, $file, 'overrides/foo.php');
+        $expected = Src\Helper\FilesystemHelper::path($instructions->getTemporaryDirectory(), 'overrides/foo.php');
+        $actual = $this->subject->write($instructions, $file, Src\Helper\FilesystemHelper::path('overrides/foo.php'));
 
         self::assertSame($expected, $actual->getPathname());
         self::assertFileExists($expected);
diff --git a/tests/src/Builder/Writer/TemplateWriterTest.php b/tests/src/Builder/Writer/TemplateWriterTest.php
index f3c597ff..9bc97f27 100644
--- a/tests/src/Builder/Writer/TemplateWriterTest.php
+++ b/tests/src/Builder/Writer/TemplateWriterTest.php
@@ -57,10 +57,10 @@ public function writeWritesRenderedTemplateFileToTemporaryDirectory(): void
         $instructions->addTemplateVariable('foo', 'foo');
         $instructions->addTemplateVariable('bar', 'foo');
 
-        $templateFile = dirname(__DIR__, 3).'/templates/dump.json.twig';
+        $templateFile = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'templates/dump.json.twig');
         $file = new Finder\SplFileInfo($templateFile, dirname($templateFile), basename($templateFile));
 
-        $expected = $instructions->getTemporaryDirectory().'/dump.json';
+        $expected = Src\Helper\FilesystemHelper::path($instructions->getTemporaryDirectory(), 'dump.json');
         $actual = $this->subject->write($instructions, $file, variables: ['bar' => 'bar']);
 
         self::assertSame($expected, $actual->getPathname());
@@ -68,8 +68,8 @@ public function writeWritesRenderedTemplateFileToTemporaryDirectory(): void
 
         $expectedJson = [
             'instructions' => [
-                'sourceDirectory' => dirname(__DIR__, 2).'/templates/src',
-                'sharedSourceDirectory' => dirname(__DIR__, 2).'/templates/shared',
+                'sourceDirectory' => Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'templates/src'),
+                'sharedSourceDirectory' => Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'templates/shared'),
             ],
             'foo' => 'foo',
             'bar' => 'bar',
@@ -91,19 +91,24 @@ public function writeWritesRenderedTemplateFileToGivenTargetFile(): void
         $instructions->addTemplateVariable('foo', 'foo');
         $instructions->addTemplateVariable('bar', 'foo');
 
-        $templateFile = dirname(__DIR__, 3).'/templates/dump.json.twig';
+        $templateFile = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 3), 'templates/dump.json.twig');
         $file = new Finder\SplFileInfo($templateFile, dirname($templateFile), basename($templateFile));
 
-        $expected = $instructions->getTemporaryDirectory().'/overrides/dump.json';
-        $actual = $this->subject->write($instructions, $file, 'overrides/dump.json.twig', ['bar' => 'bar']);
+        $expected = Src\Helper\FilesystemHelper::path($instructions->getTemporaryDirectory(), 'overrides/dump.json');
+        $actual = $this->subject->write(
+            $instructions,
+            $file,
+            Src\Helper\FilesystemHelper::path('overrides/dump.json.twig'),
+            ['bar' => 'bar'],
+        );
 
         self::assertSame($expected, $actual->getPathname());
         self::assertFileExists($expected);
 
         $expectedJson = [
             'instructions' => [
-                'sourceDirectory' => dirname(__DIR__, 2).'/templates/src',
-                'sharedSourceDirectory' => dirname(__DIR__, 2).'/templates/shared',
+                'sourceDirectory' => Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'templates/src'),
+                'sharedSourceDirectory' => Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'templates/shared'),
             ],
             'foo' => 'foo',
             'bar' => 'bar',
diff --git a/tests/src/Console/ApplicationTest.php b/tests/src/Console/ApplicationTest.php
index 467bfc06..d3f96323 100644
--- a/tests/src/Console/ApplicationTest.php
+++ b/tests/src/Console/ApplicationTest.php
@@ -54,7 +54,9 @@ protected function setUp(): void
         $this->messenger = self::$container->get('app.messenger');
         $this->filesystem = self::$container->get(Filesystem\Filesystem::class);
         $this->templateProvider = new Tests\Fixtures\DummyProvider();
-        $this->configReader = Src\Builder\Config\ConfigReader::create(dirname(__DIR__).'/Fixtures/Templates');
+        $this->configReader = Src\Builder\Config\ConfigReader::create(
+            Src\Helper\FilesystemHelper::path(dirname(__DIR__), 'Fixtures/Templates'),
+        );
         $this->subject = new Src\Console\Application(
             $this->messenger,
             $this->configReader,
@@ -84,7 +86,7 @@ public function runThrowsExceptionIfInputIsNonInteractive(): void
     #[Framework\Attributes\Test]
     public function runMirrorsSourceFilesToTemporaryDirectory(): void
     {
-        $temporaryDirectory = $this->targetDirectory.'/.build/src';
+        $temporaryDirectory = Src\Helper\FilesystemHelper::path($this->targetDirectory, '.build/src');
 
         self::assertDirectoryDoesNotExist($temporaryDirectory);
 
@@ -212,7 +214,7 @@ public function runUsesDefaultTemplateProvidersIfNoProvidersAreConfigured(): voi
 
     private function createTemplateSource(): Src\Template\TemplateSource
     {
-        $sourcePath = dirname(__DIR__).'/Fixtures/Templates/json-template';
+        $sourcePath = Src\Helper\FilesystemHelper::path(dirname(__DIR__), 'Fixtures/Templates/json-template');
         $package = Src\Resource\Local\Composer::createComposer($sourcePath)->getPackage();
 
         self::assertInstanceOf(Package\Package::class, $package);
diff --git a/tests/src/Fixtures/DummyProvider.php b/tests/src/Fixtures/DummyProvider.php
index a8b60261..cbc2582e 100644
--- a/tests/src/Fixtures/DummyProvider.php
+++ b/tests/src/Fixtures/DummyProvider.php
@@ -24,6 +24,7 @@
 namespace CPSIT\ProjectBuilder\Tests\Fixtures;
 
 use Composer\Json;
+use CPSIT\ProjectBuilder\Helper\FilesystemHelper;
 use CPSIT\ProjectBuilder\Template;
 
 /**
@@ -63,7 +64,9 @@ public function installTemplateSource(Template\TemplateSource $templateSource):
         }
 
         $package = $templateSource->getPackage();
-        $jsonFile = new Json\JsonFile($this->installationPath.'/composer.json');
+        $jsonFile = new Json\JsonFile(
+            FilesystemHelper::path($this->installationPath, 'composer.json'),
+        );
         $json = [
             'require' => [
                 $package->getName() => '*',
diff --git a/tests/src/Helper/FilesystemHelperTest.php b/tests/src/Helper/FilesystemHelperTest.php
index 56f4facd..98651a1f 100644
--- a/tests/src/Helper/FilesystemHelperTest.php
+++ b/tests/src/Helper/FilesystemHelperTest.php
@@ -47,7 +47,7 @@ public function createFileObjectReturnsFileObjectForGivenFile(): void
 
         self::assertSame($relativePathname, $actual->getRelativePathname());
         self::assertSame('.', $actual->getRelativePath());
-        self::assertSame($baseDir.'/'.$relativePathname, $actual->getPathname());
+        self::assertSame(Src\Helper\FilesystemHelper::path($baseDir, $relativePathname), $actual->getPathname());
     }
 
     #[Framework\Attributes\Test]
diff --git a/tests/src/IO/MessengerTest.php b/tests/src/IO/MessengerTest.php
index eecaf08c..ce805428 100644
--- a/tests/src/IO/MessengerTest.php
+++ b/tests/src/IO/MessengerTest.php
@@ -111,7 +111,7 @@ public function confirmTemplateSourceRetryAsksForConfirmationAndReturnsResult(st
 
         self::assertSame($expected, $this->subject->confirmTemplateSourceRetry($exception));
         self::assertStringContainsString(
-            implode(PHP_EOL, [
+            implode(LF, [
                 'Something went wrong.',
                 'You can go one step back and select another template provider.',
                 'For more information, take a look at the documentation.',
@@ -129,7 +129,7 @@ public function confirmProjectGenerationAsksForConfirmationAndReturnsResult(): v
 
         self::assertTrue($this->subject->confirmProjectRegeneration());
         self::assertStringContainsString(
-            implode(PHP_EOL, [
+            implode(LF, [
                 'If you want, you can restart project generation now.',
                 'Restart? [Y/n]',
             ]),
@@ -146,7 +146,7 @@ public function confirmProjectGenerationAsksForRunCommandAndReturnsResult(): voi
 
         self::assertTrue($this->subject->confirmRunCommand($dummyCommand));
         self::assertStringContainsString(
-            implode(PHP_EOL, [
+            implode(LF, [
                 sprintf(
                     'Preparing to run "%s" in the project dir.',
                     $dummyCommand,
diff --git a/tests/src/Resource/Local/ComposerTest.php b/tests/src/Resource/Local/ComposerTest.php
index 04ae8a1e..f256c426 100644
--- a/tests/src/Resource/Local/ComposerTest.php
+++ b/tests/src/Resource/Local/ComposerTest.php
@@ -46,7 +46,7 @@ final class ComposerTest extends Tests\ContainerAwareTestCase
     protected function setUp(): void
     {
         $this->subject = self::$container->get(Src\Resource\Local\Composer::class);
-        $this->composerJson = dirname(__DIR__, 2).'/Fixtures/Templates/yaml-template/composer.json';
+        $this->composerJson = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Templates/yaml-template/composer.json');
     }
 
     #[Framework\Attributes\Test]
diff --git a/tests/src/Template/Provider/BaseProviderTest.php b/tests/src/Template/Provider/BaseProviderTest.php
index d8d3e9d9..e3544c2d 100644
--- a/tests/src/Template/Provider/BaseProviderTest.php
+++ b/tests/src/Template/Provider/BaseProviderTest.php
@@ -355,7 +355,7 @@ private static function createPackageFromTemplateFixture(
         string $templateName = 'json-template',
         string $prettyVersion = '1.0.0',
     ): Package\Package {
-        $fixturePath = dirname(__DIR__, 2).'/Fixtures/Templates/'.$templateName;
+        $fixturePath = Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'Fixtures/Templates', $templateName);
 
         self::assertDirectoryExists($fixturePath);
 
diff --git a/tests/src/Template/Provider/ComposerProviderTest.php b/tests/src/Template/Provider/ComposerProviderTest.php
index aac06dfc..f09f9c47 100644
--- a/tests/src/Template/Provider/ComposerProviderTest.php
+++ b/tests/src/Template/Provider/ComposerProviderTest.php
@@ -96,7 +96,7 @@ public function listTemplateSourcesAddsAdditionalEmptyLineOnWrittenOutput(): voi
         $this->subject->listTemplateSources();
 
         self::assertTrue($io->isOutputWritten());
-        self::assertSame(PHP_EOL, self::$io->getOutput());
+        self::assertSame(LF, self::$io->getOutput());
     }
 
     #[Framework\Attributes\Test]
diff --git a/tests/src/Template/Provider/VcsProviderTest.php b/tests/src/Template/Provider/VcsProviderTest.php
index 6245b407..8f268bd5 100644
--- a/tests/src/Template/Provider/VcsProviderTest.php
+++ b/tests/src/Template/Provider/VcsProviderTest.php
@@ -111,7 +111,7 @@ public function listTemplateSourcesAddsAdditionalEmptyLineOnWrittenOutput(): voi
         $this->subject->listTemplateSources();
 
         self::assertTrue($io->isOutputWritten());
-        self::assertStringContainsString(PHP_EOL, self::$io->getOutput());
+        self::assertStringContainsString(LF, self::$io->getOutput());
 
         $this->filesystem->remove($repoA);
     }
@@ -187,13 +187,21 @@ public function installTemplateSourceAsksForAdditionalRepositories(): void
 
         [$templateSource] = $this->subject->listTemplateSources();
 
-        self::assertDirectoryDoesNotExist($this->temporaryRootPath.'/.build/templates/repo-a');
-        self::assertDirectoryDoesNotExist($this->temporaryRootPath.'/.build/templates/repo-b');
+        self::assertDirectoryDoesNotExist(
+            Src\Helper\FilesystemHelper::path($this->temporaryRootPath, '.build/templates/repo-a'),
+        );
+        self::assertDirectoryDoesNotExist(
+            Src\Helper\FilesystemHelper::path($this->temporaryRootPath, '.build/templates/repo-b'),
+        );
 
         $this->subject->installTemplateSource($templateSource);
 
-        self::assertDirectoryExists($this->temporaryRootPath.'/.build/templates/repo-a');
-        self::assertDirectoryExists($this->temporaryRootPath.'/.build/templates/repo-b');
+        self::assertDirectoryExists(
+            Src\Helper\FilesystemHelper::path($this->temporaryRootPath, '.build/templates/repo-a'),
+        );
+        self::assertDirectoryExists(
+            Src\Helper\FilesystemHelper::path($this->temporaryRootPath, '.build/templates/repo-b'),
+        );
 
         $output = self::$io->getOutput();
         $repositories = $this->fetchConfiguredRepositoriesViaReflection();
@@ -274,25 +282,25 @@ private function initializeGitRepository(string $composerName, array $requiremen
             $runner = self::$container->get(Cli\Command\Runner::class);
 
             // Initialize repository
-            $initCommand = (new Cli\Command\Executable('git'))
+            $initCommand = $this->createGitExecutable()
                 ->addArgument('init')
             ;
             self::assertTrue($runner->run($initCommand)->isSuccessful());
 
             // Configure author
-            $configEmailCommand = (new Cli\Command\Executable('git'))
+            $configEmailCommand = $this->createGitExecutable()
                 ->addArgument('config')
                 ->addArgument('user.email')
                 ->addArgument('noreply@example.com')
             ;
             self::assertTrue($runner->run($configEmailCommand)->isSuccessful());
-            $configNameCommand = (new Cli\Command\Executable('git'))
+            $configNameCommand = $this->createGitExecutable()
                 ->addArgument('config')
                 ->addArgument('user.name')
                 ->addArgument('Test bot')
             ;
             self::assertTrue($runner->run($configNameCommand)->isSuccessful());
-            $configSignCommand = (new Cli\Command\Executable('git'))
+            $configSignCommand = $this->createGitExecutable()
                 ->addArgument('config')
                 ->addArgument('commit.gpgsign')
                 ->addArgument('false')
@@ -300,36 +308,39 @@ private function initializeGitRepository(string $composerName, array $requiremen
             self::assertTrue($runner->run($configSignCommand)->isSuccessful());
 
             // Add composer.json
-            $this->filesystem->dumpFile($repoDir.'/composer.json', Json\JsonFile::encode([
-                'name' => $composerName,
-                'type' => 'project-builder-template',
-                'require' => $requirements,
-                'extra' => $extra,
-            ]));
+            $this->filesystem->dumpFile(
+                Src\Helper\FilesystemHelper::path($repoDir, 'composer.json'),
+                Json\JsonFile::encode([
+                    'name' => $composerName,
+                    'type' => 'project-builder-template',
+                    'require' => $requirements,
+                    'extra' => $extra,
+                ]),
+            );
 
             // Create branch
-            $checkoutCommand = (new Cli\Command\Executable('git'))
+            $checkoutCommand = $this->createGitExecutable()
                 ->addArgument('checkout')
                 ->addOption('--orphan', 'main')
             ;
             self::assertTrue($runner->run($checkoutCommand)->isSuccessful());
 
             // Add files
-            $addCommand = (new Cli\Command\Executable('git'))
+            $addCommand = $this->createGitExecutable()
                 ->addArgument('add')
                 ->addArgument('composer.json')
             ;
             self::assertTrue($runner->run($addCommand)->isSuccessful());
 
             // Commit files
-            $commitCommand = (new Cli\Command\Executable('git'))
+            $commitCommand = $this->createGitExecutable()
                 ->addArgument('commit')
                 ->addOption('--message', 'Add composer.json')
             ;
             self::assertTrue($runner->run($commitCommand)->isSuccessful());
 
             // Create tag
-            $tagCommand = (new Cli\Command\Executable('git'))
+            $tagCommand = $this->createGitExecutable()
                 ->addArgument('tag')
                 ->addArgument('1.0.0')
             ;
@@ -354,6 +365,17 @@ private static function executeInDirectory(string $directory, callable $code): v
         chdir($currentWorkingDirectory);
     }
 
+    private function createGitExecutable(): Cli\Command\Executable
+    {
+        if (PHP_OS_FAMILY === 'Windows') {
+            $binary = 'git.exe';
+        } else {
+            $binary = 'git';
+        }
+
+        return new Cli\Command\Executable($binary);
+    }
+
     protected function tearDown(): void
     {
         parent::tearDown();
diff --git a/tests/src/Twig/RendererTest.php b/tests/src/Twig/RendererTest.php
index f0dd4a99..0db98377 100644
--- a/tests/src/Twig/RendererTest.php
+++ b/tests/src/Twig/RendererTest.php
@@ -46,7 +46,7 @@ final class RendererTest extends Tests\ContainerAwareTestCase
     protected function setUp(): void
     {
         $this->subject = self::$container->get(Src\Twig\Renderer::class)
-            ->withRootPath(dirname(__DIR__, 2).'/templates')
+            ->withRootPath(Src\Helper\FilesystemHelper::path(dirname(__DIR__, 2), 'templates'))
         ;
         $this->instructions = new Src\Builder\BuildInstructions(
             self::$container->get('app.config'),
@@ -108,8 +108,8 @@ public function renderMergesBuildInstructionsAndAdditionalVariables(): void
         $actual = $this->subject->render($this->instructions, 'dump.json.twig', ['bar' => 'bar']);
         $expected = [
             'instructions' => [
-                'sourceDirectory' => dirname(__DIR__).'/templates/src',
-                'sharedSourceDirectory' => dirname(__DIR__).'/templates/shared',
+                'sourceDirectory' => Src\Helper\FilesystemHelper::path(dirname(__DIR__), 'templates/src'),
+                'sharedSourceDirectory' => Src\Helper\FilesystemHelper::path(dirname(__DIR__), 'templates/shared'),
             ],
             'foo' => 'foo',
             'bar' => 'bar',