diff --git a/config/schema/helfi_proxy.schema.yml b/config/schema/helfi_proxy.schema.yml
index 76bde22..6ccf3f0 100644
--- a/config/schema/helfi_proxy.schema.yml
+++ b/config/schema/helfi_proxy.schema.yml
@@ -13,8 +13,6 @@ helfi_proxy.settings:
         type: string
     session_suffix:
       type: string
-    robots_header_enabled:
-      type: boolean
     prefixes:
       type: sequence
       sequence:
diff --git a/helfi_proxy.install b/helfi_proxy.install
index ce8bdc3..e4951fa 100644
--- a/helfi_proxy.install
+++ b/helfi_proxy.install
@@ -63,3 +63,12 @@ function helfi_proxy_update_9002() : void {
   $loggers->set('channels', $channels)
     ->save();
 }
+
+/**
+ * Remove unused 'robots_header_enabled' config.
+ */
+function helfi_proxy_update_9003() : void {
+  \Drupal::configFactory()->getEditable('helfi_proxy.settings')
+    ->clear('robots_header_enabled')
+    ->save();
+}
diff --git a/src/EventSubscriber/RobotsResponseSubscriber.php b/src/EventSubscriber/RobotsResponseSubscriber.php
index 7a1c85b..95123f9 100644
--- a/src/EventSubscriber/RobotsResponseSubscriber.php
+++ b/src/EventSubscriber/RobotsResponseSubscriber.php
@@ -6,13 +6,11 @@
 
 use Drupal\Core\Cache\CacheableResponseInterface;
 use Drupal\Core\Config\ConfigFactoryInterface;
-use Drupal\Core\Config\ImmutableConfig;
 use Drupal\Core\Path\CurrentPathStack;
 use Drupal\Core\Path\PathMatcherInterface;
 use Drupal\helfi_proxy\ProxyManagerInterface;
 use Drupal\path_alias\AliasManagerInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
-use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\ResponseEvent;
 use Symfony\Component\HttpKernel\KernelEvents;
 
@@ -21,15 +19,6 @@
  */
 final class RobotsResponseSubscriber implements EventSubscriberInterface {
 
-  public const X_ROBOTS_TAG_HEADER_NAME = 'DRUPAL_X_ROBOTS_TAG_HEADER';
-
-  /**
-   * The config.
-   *
-   * @var \Drupal\Core\Config\ImmutableConfig
-   */
-  private ImmutableConfig $config;
-
   /**
    * Constructs a new instance.
    *
@@ -43,38 +32,11 @@ final class RobotsResponseSubscriber implements EventSubscriberInterface {
    *   The path matcher.
    */
   public function __construct(
-    ConfigFactoryInterface $configFactory,
+    private ConfigFactoryInterface $configFactory,
     private CurrentPathStack $pathStack,
     private AliasManagerInterface $aliasManager,
     private PathMatcherInterface $pathMatcher
   ) {
-    $this->config = $configFactory->get('helfi_proxy.settings');
-  }
-
-  /**
-   * Adds the robots response header.
-   *
-   * @param \Symfony\Component\HttpFoundation\Response $response
-   *   The response.
-   */
-  private function addRobotHeader(Response $response) : void {
-    $response->headers->add(['X-Robots-Tag' => 'noindex, nofollow']);
-  }
-
-  /**
-   * Checks whether robots header should be present.
-   *
-   * @return bool
-   *   TRUE if robots header is enabled for all pages.
-   */
-  private function robotsHeaderEnabled() : bool {
-    $value = $this->config->get(ProxyManagerInterface::ROBOTS_HEADER_ENABLED);
-
-    if ($value !== NULL) {
-      return (bool) $value;
-    }
-    // @todo Remove this in 3.0.0 release.
-    return (bool) getenv(self::X_ROBOTS_TAG_HEADER_NAME);
   }
 
   /**
@@ -85,26 +47,20 @@ private function robotsHeaderEnabled() : bool {
    */
   public function onResponse(ResponseEvent $event) : void {
     $response = $event->getResponse();
+    $config = $this->configFactory->get('helfi_proxy.settings');
 
-    if ($response instanceof CacheableResponseInterface) {
-      $response->addCacheableDependency($this->config);
-    }
-
-    if ($this->robotsHeaderEnabled()) {
-      $this->addRobotHeader($response);
-      // No need to check individual paths if robots header should be
-      // added for every page.
-      return;
-    }
-
-    if (!$paths = implode("\n", $this->config->get(ProxyManagerInterface::ROBOTS_PATHS) ?? [])) {
+    if (!$paths = implode("\n", $config->get(ProxyManagerInterface::ROBOTS_PATHS) ?? [])) {
       return;
     }
     $alias = $this->aliasManager
       ->getAliasByPath($this->pathStack->getPath($event->getRequest()));
 
     if ($this->pathMatcher->matchPath($alias, $paths)) {
-      $this->addRobotHeader($response);
+      $response->headers->add(['X-Robots-Tag' => 'noindex, nofollow']);
+
+      if ($response instanceof CacheableResponseInterface) {
+        $response->addCacheableDependency($config);
+      }
     }
   }
 
diff --git a/src/Plugin/DebugDataItem/Robots.php b/src/Plugin/DebugDataItem/Robots.php
deleted file mode 100644
index 4203b90..0000000
--- a/src/Plugin/DebugDataItem/Robots.php
+++ /dev/null
@@ -1,50 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Drupal\helfi_proxy\Plugin\DebugDataItem;
-
-use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
-use Drupal\helfi_api_base\DebugDataItemPluginBase;
-use Psr\Container\ContainerInterface;
-
-/**
- * Plugin implementation of the debug_data_item.
- *
- * @DebugDataItem(
- *   id = "robots",
- *   label = @Translation("Robots"),
- *   description = @Translation("Robots data")
- * )
- */
-final class Robots extends DebugDataItemPluginBase implements ContainerFactoryPluginInterface {
-
-  /**
-   * Robots header enabled settings value.
-   *
-   * @var bool
-   */
-  protected bool $robotsHeader = FALSE;
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) : self {
-    $instance = new self($configuration, $plugin_id, $plugin_definition);
-
-    $instance->robotsHeader = (bool) $container->get('config.factory')
-      ->get('helfi_proxy.settings')
-      ->get('robots_header_enabled');
-
-    return $instance;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function collect(): array {
-    $data['DRUPAL_X_ROBOTS_TAG_HEADER'] = $this->robotsHeader;
-    return $data;
-  }
-
-}
diff --git a/src/ProxyManagerInterface.php b/src/ProxyManagerInterface.php
index 76865b0..a1e5f3c 100644
--- a/src/ProxyManagerInterface.php
+++ b/src/ProxyManagerInterface.php
@@ -14,7 +14,6 @@ interface ProxyManagerInterface {
   public const ROBOTS_PATHS = 'robots_paths';
   public const FRONT_PAGE_TITLE = 'front_page_title';
   public const SESSION_SUFFIX = 'session_suffix';
-  public const ROBOTS_HEADER_ENABLED = 'robots_header_enabled';
   public const TUNNISTAMO_RETURN_URL = 'tunnistamo_return_url';
 
   /**
diff --git a/tests/src/Kernel/Plugin/DebugDataItem/RobotsTest.php b/tests/src/Kernel/Plugin/DebugDataItem/RobotsTest.php
deleted file mode 100644
index e305cec..0000000
--- a/tests/src/Kernel/Plugin/DebugDataItem/RobotsTest.php
+++ /dev/null
@@ -1,44 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Drupal\Tests\helfi_proxy\Kernel\Plugin\DebugDataItem;
-
-use Drupal\helfi_proxy\Plugin\DebugDataItem\Robots;
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests Robots debug data.
- *
- * @group helfi_proxy
- */
-class RobotsTest extends KernelTestBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  protected static $modules = [
-    'path_alias',
-    'helfi_proxy',
-  ];
-
-  /**
-   * Tests plugin when robot header setting is not enabled.
-   */
-  public function testDisabledHeader() : void {
-    $sut = Robots::create($this->container, [], 'robots', []);
-    $this->assertEquals(['DRUPAL_X_ROBOTS_TAG_HEADER' => FALSE], $sut->collect());
-  }
-
-  /**
-   * Tests plugin when robot header setting is enabled.
-   */
-  public function testHeader() : void {
-    $this->config('helfi_proxy.settings')
-      ->set('robots_header_enabled', TRUE)
-      ->save();
-    $sut = Robots::create($this->container, [], 'robots', []);
-    $this->assertEquals(['DRUPAL_X_ROBOTS_TAG_HEADER' => TRUE], $sut->collect());
-  }
-
-}
diff --git a/tests/src/Kernel/RobotsResponseSubscriberTest.php b/tests/src/Kernel/RobotsResponseSubscriberTest.php
index 734a52c..dcc5ddd 100644
--- a/tests/src/Kernel/RobotsResponseSubscriberTest.php
+++ b/tests/src/Kernel/RobotsResponseSubscriberTest.php
@@ -84,54 +84,6 @@ private function assertResponseEventNoHeader(ResponseEvent $event) : void {
     $this->assertNotContains('X-Robots-Tag', $event->getResponse()->headers);
   }
 
-  /**
-   * Tests that robots header is present when configuration is set.
-   */
-  public function testConfig() : void {
-    $this->config('helfi_proxy.settings')
-      ->set(ProxyManagerInterface::ROBOTS_HEADER_ENABLED, FALSE)
-      ->save();
-    // Make sure setting config to false does not enable the feature.
-    $event = $this->getResponseEvent();
-    $this->getSut()->onResponse($event);
-    $this->assertResponseEventNoHeader($event);
-
-    $this->config('helfi_proxy.settings')
-      ->set(ProxyManagerInterface::ROBOTS_HEADER_ENABLED, TRUE)
-      ->save();
-    $event = $this->getResponseEvent();
-    $this->getSut()->onResponse($event);
-    $this->assertResponseEventHasHeader($event);
-  }
-
-  /**
-   * Tests that robots header is not present when no env variable is set.
-   */
-  public function testNoEnvVariable() : void {
-    $event = $this->getResponseEvent();
-    $this->getSut()->onResponse($event);
-    $this->assertResponseEventNoHeader($event);
-
-    // Make sure setting null values to robots env variable does not
-    // enable the feature.
-    foreach ([0, NULL, ''] as $value) {
-      putenv(RobotsResponseSubscriber::X_ROBOTS_TAG_HEADER_NAME . '=' . $value);
-      $event = $this->getResponseEvent();
-      $this->getSut()->onResponse($event);
-      $this->assertResponseEventNoHeader($event);
-    }
-  }
-
-  /**
-   * Tests that robots header is added when env variable is present.
-   */
-  public function testEnvVariable() : void {
-    putenv(RobotsResponseSubscriber::X_ROBOTS_TAG_HEADER_NAME . '=1');
-    $event = $this->getResponseEvent();
-    $this->getSut()->onResponse($event);
-    $this->assertResponseEventHasHeader($event);
-  }
-
   /**
    * Tests robots path handler.
    */