diff --git a/composer.json b/composer.json
index 6ec3125e..690d44b9 100644
--- a/composer.json
+++ b/composer.json
@@ -61,8 +61,9 @@
     "config": {
         "allow-plugins": {
             "dealerdirect/phpcodesniffer-composer-installer": true,
+            "infection/extension-installer": true,
             "phpstan/extension-installer": true,
-            "infection/extension-installer": true
+            "ocramius/package-versions": true
         },
         "preferred-install": "dist",
         "sort-packages": true
diff --git a/src/Config/ContainerConfiguration.php b/src/Config/ContainerConfiguration.php
index f96b31ef..1561a782 100644
--- a/src/Config/ContainerConfiguration.php
+++ b/src/Config/ContainerConfiguration.php
@@ -158,7 +158,7 @@ public function getBaseClass(): ?string
 
     public function setBaseClass(string $baseClass): void
     {
-        $this->baseClass = $baseClass;
+        $this->baseClass = '\\' . ltrim($baseClass, '\\');
     }
 
     public function withSubNamespace(string $namespace): self
diff --git a/test/CompilationWithBaseClassTest.php b/test/CompilationWithBaseClassTest.php
new file mode 100644
index 00000000..78e70a41
--- /dev/null
+++ b/test/CompilationWithBaseClassTest.php
@@ -0,0 +1,34 @@
+<?php
+declare(strict_types=1);
+
+namespace Lcobucci\DependencyInjection;
+
+use Lcobucci\DependencyInjection\Compiler\ParameterBag;
+use Lcobucci\DependencyInjection\Config\ContainerConfiguration;
+use Lcobucci\DependencyInjection\Generators\Xml;
+use PHPUnit\Framework\Attributes as PHPUnit;
+use PHPUnit\Framework\TestCase;
+
+#[PHPUnit\CoversClass(ContainerBuilder::class)]
+#[PHPUnit\CoversClass(Compiler::class)]
+#[PHPUnit\CoversClass(ParameterBag::class)]
+#[PHPUnit\CoversClass(ContainerConfiguration::class)]
+#[PHPUnit\CoversClass(Generator::class)]
+#[PHPUnit\CoversClass(Xml::class)]
+final class CompilationWithBaseClassTest extends TestCase
+{
+    use GeneratesDumpDirectory;
+
+    private const DI_NAMESPACE = 'Lcobucci\\DiTests\\BaseClass';
+
+    #[PHPUnit\Test]
+    public function containerCanHaveACustomBaseClass(): void
+    {
+        $container = ContainerBuilder::xml(__FILE__, self::DI_NAMESPACE)
+            ->setBaseClass(ContainerForTests::class)
+            ->setDumpDir($this->dumpDirectory)
+            ->getContainer();
+
+        self::assertInstanceOf(ContainerForTests::class, $container);
+    }
+}
diff --git a/test/CompilerTest.php b/test/CompilerTest.php
index 495e5906..8dc7ecbb 100644
--- a/test/CompilerTest.php
+++ b/test/CompilerTest.php
@@ -21,7 +21,6 @@
 use function file_get_contents;
 use function file_put_contents;
 use function iterator_to_array;
-use function mkdir;
 
 #[PHPUnit\CoversClass(Compiler::class)]
 #[PHPUnit\UsesClass(ParameterBag::class)]
@@ -31,6 +30,8 @@
 #[PHPUnit\UsesClass(MakeServicesPublic::class)]
 final class CompilerTest extends TestCase
 {
+    use GeneratesDumpDirectory;
+
     private const EXPECTED_FILES = [
         'getTestingService.php',
         'AppContainer.php',
@@ -40,7 +41,6 @@ final class CompilerTest extends TestCase
 
     private ContainerConfiguration $config;
     private ConfigCache $dump;
-    private string $dumpDir;
     private ParameterBag $parameters;
 
     #[PHPUnit\Before]
@@ -57,8 +57,7 @@ public function configureDependencies(): void
         $this->parameters->set('container.dumper.inline_factories', false);
         $this->parameters->set('container.dumper.inline_class_loader', true);
 
-        $this->dumpDir = $this->createDumpDirectory();
-        $this->dump    = new ConfigCache($this->dumpDir . '/AppContainer.php', false);
+        $this->dump = new ConfigCache($this->dumpDirectory . '/AppContainer.php', false);
 
         $this->config = new ContainerConfiguration(
             'Me\\CompilationTest',
@@ -69,15 +68,7 @@ public function configureDependencies(): void
             ],
         );
 
-        $this->config->setDumpDir($this->dumpDir);
-    }
-
-    private function createDumpDirectory(): string
-    {
-        $dir = vfsStream::url('tests-compilation/tmp/me_myapp');
-        mkdir($dir, 0777, true);
-
-        return $dir;
+        $this->config->setDumpDir($this->dumpDirectory);
     }
 
     #[PHPUnit\Test]
@@ -123,7 +114,7 @@ public function compileShouldTrackChangesOnTheConfigurationFile(): void
 
         self::assertStringContainsString(
             __FILE__,
-            (string) file_get_contents($this->dumpDir . '/AppContainer.php.meta'),
+            (string) file_get_contents($this->dumpDirectory . '/AppContainer.php.meta'),
         );
     }
 
@@ -147,7 +138,7 @@ public function compileShouldAllowForLazyServices(): void
     #[PHPUnit\Test]
     public function compilationShouldBeSkippedWhenFileAlreadyExists(): void
     {
-        file_put_contents($this->dumpDir . '/AppContainer.php', 'testing');
+        file_put_contents($this->dumpDirectory . '/AppContainer.php', 'testing');
 
         $compiler = new Compiler();
         $compiler->compile($this->config, $this->dump, new Yaml(__FILE__));
@@ -167,7 +158,7 @@ public function compileShouldUseCustomContainerBuilders(): void
             new Yaml(__FILE__, CustomContainerBuilderForTests::class),
         );
 
-        $container = include $this->dumpDir . '/AppContainer.php';
+        $container = include $this->dumpDirectory . '/AppContainer.php';
 
         self::assertInstanceOf(Container::class, $container);
         self::assertTrue($container->hasParameter('built-with-very-special-builder'));
@@ -177,7 +168,7 @@ public function compileShouldUseCustomContainerBuilders(): void
     /** @return PHPGenerator<string, SplFileInfo> */
     private function getGeneratedFiles(?string $dir = null): PHPGenerator
     {
-        $dir ??= $this->dumpDir;
+        $dir ??= $this->dumpDirectory;
 
         foreach (new DirectoryIterator($dir) as $fileInfo) {
             if ($fileInfo->isDot()) {
diff --git a/test/Config/ContainerConfigurationTest.php b/test/Config/ContainerConfigurationTest.php
index b3cd8c89..61f24551 100644
--- a/test/Config/ContainerConfigurationTest.php
+++ b/test/Config/ContainerConfigurationTest.php
@@ -249,7 +249,16 @@ public function setBaseClassShouldChangeTheAttribute(): void
         $config = new ContainerConfiguration('Me\\MyApp');
         $config->setBaseClass('Test');
 
-        self::assertSame('Test', $config->getBaseClass());
+        self::assertSame('\\Test', $config->getBaseClass());
+    }
+
+    #[PHPUnit\Test]
+    public function setBaseClassShouldTrimTheLeadingSlash(): void
+    {
+        $config = new ContainerConfiguration('Me\\MyApp');
+        $config->setBaseClass('\\Test');
+
+        self::assertSame('\\Test', $config->getBaseClass());
     }
 
     #[PHPUnit\Test]
@@ -302,7 +311,7 @@ public function getDumpOptionsShouldIncludeBaseWhenWasConfigured(): void
         $options = [
             'class'        => ContainerConfiguration::CLASS_NAME,
             'namespace'    => 'Me\\MyApp',
-            'base_class'   => 'Test',
+            'base_class'   => '\\Test',
             'hot_path_tag' => 'container.hot_path',
         ];
 
diff --git a/test/ContainerBuilderTest.php b/test/ContainerBuilderTest.php
index 4ecdf88d..18cc9d1f 100644
--- a/test/ContainerBuilderTest.php
+++ b/test/ContainerBuilderTest.php
@@ -176,7 +176,7 @@ public function setBaseClassShouldConfigureTheBaseClassAndReturnSelf(): void
         $builder = new ContainerBuilder($this->config, $this->generator, $this->parameterBag);
 
         self::assertSame($builder, $builder->setBaseClass('Test'));
-        self::assertEquals('Test', $this->config->getBaseClass());
+        self::assertEquals('\\Test', $this->config->getBaseClass());
     }
 
     #[PHPUnit\Test]
diff --git a/test/ContainerForTests.php b/test/ContainerForTests.php
new file mode 100644
index 00000000..bdb119f5
--- /dev/null
+++ b/test/ContainerForTests.php
@@ -0,0 +1,10 @@
+<?php
+declare(strict_types=1);
+
+namespace Lcobucci\DependencyInjection;
+
+use Symfony\Component\DependencyInjection\Container;
+
+abstract class ContainerForTests extends Container
+{
+}
diff --git a/test/GeneratesDumpDirectory.php b/test/GeneratesDumpDirectory.php
new file mode 100644
index 00000000..f9be3555
--- /dev/null
+++ b/test/GeneratesDumpDirectory.php
@@ -0,0 +1,37 @@
+<?php
+declare(strict_types=1);
+
+namespace Lcobucci\DependencyInjection;
+
+use PHPUnit\Framework\Attributes as PHPUnit;
+
+use function assert;
+use function exec;
+use function is_string;
+use function mkdir;
+use function tempnam;
+use function unlink;
+
+trait GeneratesDumpDirectory
+{
+    private string $dumpDirectory;
+
+    #[PHPUnit\Before]
+    public function createDumpDir(): void
+    {
+        mkdir(__DIR__ . '/../tmp');
+
+        $tempName = tempnam(__DIR__ . '/../tmp', 'lcobucci-di-builder');
+        assert(is_string($tempName));
+
+        $this->dumpDirectory = $tempName;
+        unlink($this->dumpDirectory);
+        mkdir($this->dumpDirectory);
+    }
+
+    #[PHPUnit\After]
+    public function removeDumpDir(): void
+    {
+        exec('rm -rf ' . __DIR__ . '/../tmp');
+    }
+}
diff --git a/test/GeneratorTest.php b/test/GeneratorTest.php
index 807470e0..4f3af354 100644
--- a/test/GeneratorTest.php
+++ b/test/GeneratorTest.php
@@ -6,37 +6,33 @@
 use Lcobucci\DependencyInjection\Compiler\DumpXmlContainer;
 use Lcobucci\DependencyInjection\Compiler\ParameterBag;
 use Lcobucci\DependencyInjection\Config\ContainerConfiguration;
+use Lcobucci\DependencyInjection\Generators\Yaml;
 use org\bovigo\vfs\vfsStream;
 use PHPUnit\Framework\Attributes as PHPUnit;
-use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
 use stdClass;
 use Symfony\Component\Config\ConfigCache;
-use Symfony\Component\Config\FileLocator;
 use Symfony\Component\Config\Resource\FileResource;
 use Symfony\Component\DependencyInjection\Compiler\PassConfig;
-use Symfony\Component\DependencyInjection\ContainerBuilder as SymfonyBuilder;
-use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 
 #[PHPUnit\CoversClass(Generator::class)]
 #[PHPUnit\UsesClass(ParameterBag::class)]
 #[PHPUnit\UsesClass(ContainerConfiguration::class)]
 #[PHPUnit\UsesClass(DumpXmlContainer::class)]
 #[PHPUnit\UsesClass(Compiler::class)]
+#[PHPUnit\UsesClass(Yaml::class)]
 final class GeneratorTest extends TestCase
 {
-    private Generator&MockObject $generator;
+    use GeneratesDumpDirectory;
 
-    #[PHPUnit\Before]
-    public function configureDependencies(): void
-    {
-        $this->generator = $this->getMockForAbstractClass(Generator::class, [__FILE__]);
-    }
+    private const DI_NAMESPACE = 'Lcobucci\\DiTests\\Generator';
 
     #[PHPUnit\Test]
     public function initializeContainerShouldAddTheConfigurationFileAsAResource(): void
     {
-        $container = $this->generator->initializeContainer(new ContainerConfiguration('Me\\MyApp'));
+        $container = (new Yaml(__FILE__))->initializeContainer(
+            new ContainerConfiguration(self::DI_NAMESPACE),
+        );
 
         self::assertEquals([new FileResource(__FILE__)], $container->getResources());
     }
@@ -65,34 +61,23 @@ public function generateShouldCompileAndLoadTheContainer(): void
         );
 
         $config = new ContainerConfiguration(
-            'Me\\GenerationTest',
+            self::DI_NAMESPACE,
             [vfsStream::url('tests-generation/services.yml')],
             [
                 [new ParameterBag(['app.devmode' => true]), PassConfig::TYPE_BEFORE_OPTIMIZATION],
                 [
-                    new DumpXmlContainer(
-                        new ConfigCache(vfsStream::url('tests-generation/dump.xml'), true),
-                    ),
+                    new DumpXmlContainer(new ConfigCache($this->dumpDirectory . '/dump.xml', true)),
                     PassConfig::TYPE_AFTER_REMOVING,
                     -255,
                 ],
             ],
         );
 
-        $dump = new ConfigCache(vfsStream::url('tests-generation/container.php'), false);
-
-        $this->generator->method('getLoader')->willReturnCallback(
-            static function (SymfonyBuilder $container, array $paths): YamlFileLoader {
-                return new YamlFileLoader(
-                    $container,
-                    new FileLocator($paths),
-                );
-            },
-        );
+        $dump = new ConfigCache($this->dumpDirectory . '/container.php', false);
 
-        $container = $this->generator->generate($config, $dump);
+        $container = (new Yaml(__FILE__))->generate($config, $dump);
 
         self::assertInstanceOf(stdClass::class, $container->get('testing'));
-        self::assertFileExists(vfsStream::url('tests-generation/dump.xml'));
+        self::assertFileExists($this->dumpDirectory . '/dump.xml');
     }
 }