diff --git a/seckit.services.yml b/seckit.services.yml
index 87ea11a15..89e2519a5 100644
--- a/seckit.services.yml
+++ b/seckit.services.yml
@@ -1,7 +1,7 @@
 services:
   seckit.subscriber:
     class: Drupal\seckit\EventSubscriber\SecKitEventSubscriber
-    arguments: ['@logger.channel.seckit', '@config.factory']
+    arguments: ['@logger.channel.seckit', '@config.factory', '@module_handler']
     tags:
       - { name: event_subscriber }
   logger.channel.seckit:
diff --git a/src/EventSubscriber/SecKitEventSubscriber.php b/src/EventSubscriber/SecKitEventSubscriber.php
index 42b1f8740..1bad8438f 100644
--- a/src/EventSubscriber/SecKitEventSubscriber.php
+++ b/src/EventSubscriber/SecKitEventSubscriber.php
@@ -5,6 +5,7 @@
 use Drupal\Component\Utility\Xss;
 use Drupal\Component\Utility\UrlHelper;
 use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\seckit\SeckitInterface;
 use Psr\Log\LoggerInterface;
@@ -49,6 +50,13 @@ class SecKitEventSubscriber implements EventSubscriberInterface {
    */
   protected $logger;

+  /**
+   * Module handler.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
   /**
    * Constructs an SecKitEventSubscriber object.
    *
@@ -57,9 +65,10 @@ class SecKitEventSubscriber implements EventSubscriberInterface {
    * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct(LoggerInterface $logger, ConfigFactoryInterface $config_factory) {
+  public function __construct(LoggerInterface $logger, ConfigFactoryInterface $config_factory, ModuleHandlerInterface $module_handler) {
     $this->logger = $logger;
     $this->config = $config_factory->get('seckit.settings');
+    $this->moduleHandler = $module_handler;
   }

   /**
@@ -223,37 +232,37 @@ public function seckitCsp() {
     // Otherwise prepare directives.
     // else {.
     if ($csp_default_src) {
-      $directives[] = "default-src $csp_default_src";
+      $directives['default-src'] = "default-src $csp_default_src";
     }
     if ($csp_script_src) {
-      $directives[] = "script-src $csp_script_src";
+      $directives['script-src'] = "script-src $csp_script_src";
     }
     if ($csp_object_src) {
-      $directives[] = "object-src $csp_object_src";
+      $directives['object-src'] = "object-src $csp_object_src";
     }
     if ($csp_style_src) {
-      $directives[] = "style-src $csp_style_src";
+      $directives['style-src'] = "style-src $csp_style_src";
     }
     if ($csp_img_src) {
-      $directives[] = "img-src $csp_img_src";
+      $directives['img-src'] = "img-src $csp_img_src";
     }
     if ($csp_media_src) {
-      $directives[] = "media-src $csp_media_src";
+      $directives['media-src'] = "media-src $csp_media_src";
     }
     if ($csp_frame_src) {
-      $directives[] = "frame-src $csp_frame_src";
+      $directives['frame-src'] = "frame-src $csp_frame_src";
     }
     if ($csp_frame_ancestors) {
-      $directives[] = "frame-ancestors $csp_frame_ancestors";
+      $directives['frame-ancestors'] = "frame-ancestors $csp_frame_ancestors";
     }
     if ($csp_child_src) {
-      $directives[] = "child-src $csp_child_src";
+      $directives['child-src'] = "child-src $csp_child_src";
     }
     if ($csp_font_src) {
-      $directives[] = "font-src $csp_font_src";
+      $directives['font-src'] = "font-src $csp_font_src";
     }
     if ($csp_connect_src) {
-      $directives[] = "connect-src $csp_connect_src";
+      $directives['connect-src'] = "connect-src $csp_connect_src";
     }
     if ($csp_report_uri) {
       $base_path = '';
@@ -264,11 +273,14 @@ public function seckitCsp() {
         $csp_report_uri = ltrim($csp_report_uri, '/');
         $base_path = base_path();
       }
-      $directives[] = "report-uri " . $base_path . $csp_report_uri;
+      $directives['report-uri'] = "report-uri " . $base_path . $csp_report_uri;
     }
     if ($csp_upgrade_req) {
-      $directives[] = 'upgrade-insecure-requests';
+      $directives['upgrade-insecure-requests'] = 'upgrade-insecure-requests';
     }
+
+    $this->moduleHandler->alter('seckit_csp_directives', $directives);
+
     // Merge directives.
     $directives = implode('; ', $directives);
     // }