diff --git a/CHANGELOG.md b/CHANGELOG.md
index f7b5f75..bc9aa07 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@ Latest
 ------
 
 ### Changes
+* [#47](https://github.com/cleverage/archive-process-bundle/issues/47) Configuring a key under `clever_age_archive_process` is deprecated: the bundle has no configuration and the keys were ignored without notice (new internal `Configuration`, empty; notice when the container is compiled). They will be rejected in 3.0. Require `symfony/deprecation-contracts`, used directly. Update documentation, add tests.
 * [#45](https://github.com/cleverage/archive-process-bundle/issues/45) The bundle throws exceptions implementing `ProcessExceptionInterface` of the process bundle instead of raw SPL exceptions (as [cleverage/process-bundle#317](https://github.com/cleverage/process-bundle/issues/317)): new `Exception\UnexpectedValueException` and `Exception\RuntimeException`, extending the SPL exceptions thrown before (same messages, the existing `catch` keep working). Add tests.
 * [#43](https://github.com/cleverage/archive-process-bundle/issues/43) Composer: require PHP `^8.2` instead of `>=8.2` (PHP 9 is no longer accepted before being tested), remove the authorization of the `symfony/flex` plugin, which is not required (the CI installs it globally), as [cleverage/process-bundle#319](https://github.com/cleverage/process-bundle/issues/319).
 * [#38](https://github.com/cleverage/archive-process-bundle/issues/38) Define the public API (Symfony BC promise, as [cleverage/process-bundle#279](https://github.com/cleverage/process-bundle/issues/279)): `ZipTask`, `UnzipTask` and `CleverAgeArchiveProcessBundle` are marked `@final since 2.3`, they will be `final` in 3.0: extending them triggers a deprecation with the Symfony `DebugClassLoader`. `CleverAgeArchiveProcessExtension` is marked `@internal`.
diff --git a/composer.json b/composer.json
index 9176070..ecddd15 100644
--- a/composer.json
+++ b/composer.json
@@ -42,6 +42,7 @@
     "cleverage/process-bundle": "^5.0",
     "symfony/config": "^6.4|^7.4|^8",
     "symfony/dependency-injection": "^6.4|^7.4|^8",
+    "symfony/deprecation-contracts": "^2.5|^3",
     "symfony/http-kernel": "^6.4|^7.4|^8",
     "symfony/options-resolver": "^6.4|^7.4|^8",
     "symfony/polyfill-php83": "^1.33",
diff --git a/docs/index.md b/docs/index.md
index 2f48301..0f30cdf 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -42,6 +42,8 @@ will be private in 3.0); their former ids, `cleverage_archive_process.task.zip`
 Both tasks accept their options either from the task configuration or from their input (an array merged with the
 options), which allows computing paths in a previous task.
 
+No option can be configured under `clever_age_archive_process`: a key there is ignored. Configuring one is deprecated since 2.3 (an `E_USER_DEPRECATED` error is triggered when the container is compiled), the keys will be rejected in 3.0.
+
 ## Documentation
 
 - Cookbooks
diff --git a/src/DependencyInjection/CleverAgeArchiveProcessExtension.php b/src/DependencyInjection/CleverAgeArchiveProcessExtension.php
index df752ed..9da5e76 100644
--- a/src/DependencyInjection/CleverAgeArchiveProcessExtension.php
+++ b/src/DependencyInjection/CleverAgeArchiveProcessExtension.php
@@ -25,6 +25,18 @@ class CleverAgeArchiveProcessExtension extends Extension
 {
     public function load(array $configs, ContainerBuilder $container): void
     {
+        $keys = array_keys(array_merge(...$configs));
+        if ([] !== $keys) {
+            trigger_deprecation(
+                'cleverage/archive-process-bundle',
+                '2.3',
+                'Configuring "%s" is deprecated, the bundle has no configuration: the keys "%s" are ignored. They will be rejected in 3.0.',
+                $this->getAlias(),
+                implode('", "', $keys),
+            );
+        }
+        $this->processConfiguration(new Configuration(), $configs);
+
         $this->findServices($container, __DIR__.'/../../config/services');
     }
 
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
new file mode 100644
index 0000000..419fdb8
--- /dev/null
+++ b/src/DependencyInjection/Configuration.php
@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the CleverAge/ArchiveProcessBundle package.
+ *
+ * Copyright (c) Clever-Age
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CleverAge\ArchiveProcessBundle\DependencyInjection;
+
+use Symfony\Component\Config\Definition\Builder\ArrayNodeDefinition;
+use Symfony\Component\Config\Definition\Builder\TreeBuilder;
+use Symfony\Component\Config\Definition\ConfigurationInterface;
+
+/**
+ * The bundle has no option: the configured keys are ignored with a deprecation (see CleverAgeArchiveProcessExtension::load()), they will be
+ * rejected in 3.0.
+ *
+ * @internal
+ */
+final class Configuration implements ConfigurationInterface
+{
+    public function getConfigTreeBuilder(): TreeBuilder
+    {
+        $treeBuilder = new TreeBuilder('clever_age_archive_process');
+        /** @var ArrayNodeDefinition $rootNode */
+        $rootNode = $treeBuilder->getRootNode();
+        $rootNode->ignoreExtraKeys();
+
+        return $treeBuilder;
+    }
+}
diff --git a/tests/DependencyInjection/CleverAgeArchiveProcessExtensionTest.php b/tests/DependencyInjection/CleverAgeArchiveProcessExtensionTest.php
index 30f8918..2bb7d38 100644
--- a/tests/DependencyInjection/CleverAgeArchiveProcessExtensionTest.php
+++ b/tests/DependencyInjection/CleverAgeArchiveProcessExtensionTest.php
@@ -14,6 +14,7 @@
 namespace CleverAge\ArchiveProcessBundle\Tests\DependencyInjection;
 
 use CleverAge\ArchiveProcessBundle\DependencyInjection\CleverAgeArchiveProcessExtension;
+use CleverAge\ArchiveProcessBundle\DependencyInjection\Configuration;
 use CleverAge\ArchiveProcessBundle\Task\UnzipTask;
 use CleverAge\ArchiveProcessBundle\Task\ZipTask;
 use PHPUnit\Framework\Attributes\CoversClass;
@@ -23,6 +24,7 @@
 use Symfony\Component\Yaml\Yaml;
 
 #[CoversClass(CleverAgeArchiveProcessExtension::class)]
+#[CoversClass(Configuration::class)]
 class CleverAgeArchiveProcessExtensionTest extends TestCase
 {
     public function testEveryServiceDefinitionFileIsLoaded(): void
@@ -96,4 +98,52 @@ public function testTaskIsRegistered(string $class, string $code, string $deprec
             $alias->getDeprecation($deprecatedId)
         );
     }
+
+    public function testConfigurationKeysAreDeprecated(): void
+    {
+        $deprecations = $this->collectDeprecations(static function (): void {
+            (new CleverAgeArchiveProcessExtension())->load([[], ['foo' => true], ['bar' => 1, 'foo' => false]], new ContainerBuilder());
+        });
+
+        self::assertSame(['Since cleverage/archive-process-bundle 2.3: Configuring "clever_age_archive_process" is deprecated, the bundle has no configuration: the keys "foo", "bar" are ignored. They will be rejected in 3.0.'], $deprecations);
+    }
+
+    public function testNoDeprecationWithoutConfigurationKey(): void
+    {
+        $deprecations = $this->collectDeprecations(static function (): void {
+            (new CleverAgeArchiveProcessExtension())->load([[], []], new ContainerBuilder());
+        });
+
+        self::assertSame([], $deprecations);
+    }
+
+    public function testConfigurationHasNoOption(): void
+    {
+        $configuration = (new CleverAgeArchiveProcessExtension())->getConfiguration([], new ContainerBuilder());
+
+        self::assertInstanceOf(Configuration::class, $configuration);
+        self::assertSame('clever_age_archive_process', $configuration->getConfigTreeBuilder()->buildTree()->getName());
+    }
+
+    /**
+     * @param callable(): void $callback
+     *
+     * @return list<string>
+     */
+    private function collectDeprecations(callable $callback): array
+    {
+        $deprecations = [];
+        set_error_handler(static function (int $errno, string $errstr) use (&$deprecations): bool {
+            $deprecations[] = $errstr;
+
+            return true;
+        }, \E_USER_DEPRECATED);
+        try {
+            $callback();
+        } finally {
+            restore_error_handler();
+        }
+
+        return $deprecations;
+    }
 }