diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9dc35a..7309ff4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,11 @@ before starting to add changes. Use example [placed in the end of the page](#exa
 
 ## [Unreleased]
 
+## [3.21.2] 2025-01-07
+
+- Adds missing `http-message-util` requirement and use statement.
+- Runs code-analysis on `os2forms_fbs_handler` module.
+
 ## [3.21.1] 2025-01-06
 
 - Updated Maestro notification handler assignment message format.
@@ -328,7 +333,8 @@ before starting to add changes. Use example [placed in the end of the page](#exa
 - Security in case of vulnerabilities.
 ```
 
-[Unreleased]: https://github.com/OS2Forms/os2forms/compare/3.21.1...HEAD
+[Unreleased]: https://github.com/OS2Forms/os2forms/compare/3.21.2...HEAD
+[3.21.2]: https://github.com/OS2Forms/os2forms/compare/3.21.1...3.21.2
 [3.21.1]: https://github.com/OS2Forms/os2forms/compare/3.21.0...3.21.1
 [3.21.0]: https://github.com/OS2Forms/os2forms/compare/3.20.1...3.21.0
 [3.20.1]: https://github.com/OS2Forms/os2forms/compare/3.20.0...3.20.1
diff --git a/composer.json b/composer.json
index 401909b..fdbcb4f 100644
--- a/composer.json
+++ b/composer.json
@@ -65,6 +65,7 @@
         "drupal/webform_validation": "^2.0",
         "drupal/webform_views": "^5.0@alpha",
         "drupal/workflow_participants": "^3.0@RC",
+        "fig/http-message-util": "^1.1",
         "http-interop/http-factory-guzzle": "^1.0.0",
         "itk-dev/beskedfordeler-drupal": "^1.0",
         "itk-dev/serviceplatformen": "^1.5",
diff --git a/modules/os2forms_fbs_handler/src/Client/FBS.php b/modules/os2forms_fbs_handler/src/Client/FBS.php
index 44b8f6a..66c38b4 100644
--- a/modules/os2forms_fbs_handler/src/Client/FBS.php
+++ b/modules/os2forms_fbs_handler/src/Client/FBS.php
@@ -4,6 +4,7 @@
 
 use Drupal\os2forms_fbs_handler\Client\Model\Guardian;
 use Drupal\os2forms_fbs_handler\Client\Model\Patron;
+use Fig\Http\Message\RequestMethodInterface;
 use GuzzleHttp\Client;
 use Symfony\Component\HttpFoundation\Request;
 
@@ -242,6 +243,8 @@ public function createGuardian(Patron $patron, Guardian $guardian): int {
    *
    * @throws \GuzzleHttp\Exception\GuzzleException
    * @throws \JsonException
+   *
+   * @phpstan-param array<mixed>|string $data
    */
   private function request(string $uri, array|string $data, string $method = Request::METHOD_POST): mixed {
     $url = rtrim($this->endpoint, '/\\');
diff --git a/modules/os2forms_fbs_handler/src/Client/Model/Guardian.php b/modules/os2forms_fbs_handler/src/Client/Model/Guardian.php
index 371d3bb..b72a648 100644
--- a/modules/os2forms_fbs_handler/src/Client/Model/Guardian.php
+++ b/modules/os2forms_fbs_handler/src/Client/Model/Guardian.php
@@ -22,6 +22,8 @@ public function __construct(
    *
    * @return array
    *   Array with field required by FBS calls.
+   *
+   * @phpstan-return array<string, string>
    */
   public function toArray(): array {
     return [
diff --git a/modules/os2forms_fbs_handler/src/Client/Model/Patron.php b/modules/os2forms_fbs_handler/src/Client/Model/Patron.php
index e5e7d56..db3e1d0 100644
--- a/modules/os2forms_fbs_handler/src/Client/Model/Patron.php
+++ b/modules/os2forms_fbs_handler/src/Client/Model/Patron.php
@@ -9,6 +9,10 @@ final class Patron {
 
   /**
    * Default constructor.
+   *
+   * @phpstan-param array<mixed>|null $notificationProtocols
+   * @phpstan-param array<mixed>|null $onHold
+   * @phpstan-param array<mixed>|null $emailAddresses
    */
   public function __construct(
     public readonly ?string $patronId = NULL,
@@ -35,6 +39,8 @@ public function __construct(
    *
    * @return array
    *   Array with field required by FBS calls.
+   *
+   * @phpstan-return array<string, string>
    */
   public function toArray(): array {
     return [
diff --git a/modules/os2forms_fbs_handler/src/Plugin/AdvancedQueue/JobType/FbsCreateUser.php b/modules/os2forms_fbs_handler/src/Plugin/AdvancedQueue/JobType/FbsCreateUser.php
index 179d0a1..d5de9af 100644
--- a/modules/os2forms_fbs_handler/src/Plugin/AdvancedQueue/JobType/FbsCreateUser.php
+++ b/modules/os2forms_fbs_handler/src/Plugin/AdvancedQueue/JobType/FbsCreateUser.php
@@ -35,6 +35,8 @@ final class FbsCreateUser extends JobTypeBase implements ContainerFactoryPluginI
 
   /**
    * {@inheritdoc}
+   *
+   * @phpstan-param array<mixed> $configuration
    */
   public function __construct(
     array $configuration,
@@ -50,6 +52,8 @@ public function __construct(
 
   /**
    * {@inheritdoc}
+   *
+   * @phpstan-param array<mixed> $configuration
    */
   public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
     return new static(
diff --git a/modules/os2forms_fbs_handler/src/Plugin/WebformHandler/FbsWebformHandler.php b/modules/os2forms_fbs_handler/src/Plugin/WebformHandler/FbsWebformHandler.php
index 2562514..1c2abad 100644
--- a/modules/os2forms_fbs_handler/src/Plugin/WebformHandler/FbsWebformHandler.php
+++ b/modules/os2forms_fbs_handler/src/Plugin/WebformHandler/FbsWebformHandler.php
@@ -45,6 +45,8 @@ final class FbsWebformHandler extends WebformHandlerBase {
 
   /**
    * Constructs an FbsWebformHandler object.
+   *
+   * @phpstan-param array<mixed> $configuration
    */
   public function __construct(
     array $configuration,
@@ -70,6 +72,8 @@ public function __construct(
 
   /**
    * {@inheritdoc}
+   *
+   * @phpstan-param array<mixed> $configuration
    */
   public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
     return new static(
@@ -87,6 +91,10 @@ public static function create(ContainerInterface $container, array $configuratio
 
   /**
    * {@inheritdoc}
+   *
+   * @phpstan-param array<mixed> $form
+   *
+   * @phpstan-return array<mixed>
    */
   public function buildConfigurationForm(array $form, FormStateInterface $form_state): array {
     if (is_null($this->getQueue())) {
@@ -143,6 +151,8 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
 
   /**
    * {@inheritdoc}
+   *
+   * @phpstan-param array<mixed> $form
    */
   public function submitConfigurationForm(array &$form, FormStateInterface $form_state): void {
     parent::submitConfigurationForm($form, $form_state);
diff --git a/phpstan.neon b/phpstan.neon
index 8ece9b1..dd1fcc1 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -2,6 +2,7 @@ parameters:
   level: 6
   paths:
     - modules/os2forms_digital_post/
+    - modules/os2forms_fbs_handler/
   excludePaths:
     # @see https://github.com/mglaman/drupal-check/issues/261#issuecomment-1030141772/
     - vendor