diff --git a/src/Storageless/Http/ClientFingerprint/Configuration.php b/src/Storageless/Http/ClientFingerprint/Configuration.php
index c243dabe..616af9fd 100644
--- a/src/Storageless/Http/ClientFingerprint/Configuration.php
+++ b/src/Storageless/Http/ClientFingerprint/Configuration.php
@@ -4,11 +4,11 @@
 
 namespace PSR7Sessions\Storageless\Http\ClientFingerprint;
 
-/** @immutable */
-final class Configuration
+/** @psalm-immutable */
+final readonly class Configuration
 {
     /** @var list<Source> */
-    private readonly array $sources;
+    private array $sources;
 
     /**
      * @param list<Source> ...$sources
diff --git a/src/Storageless/Http/ClientFingerprint/RemoteAddr.php b/src/Storageless/Http/ClientFingerprint/RemoteAddr.php
index fec669dd..252e4052 100644
--- a/src/Storageless/Http/ClientFingerprint/RemoteAddr.php
+++ b/src/Storageless/Http/ClientFingerprint/RemoteAddr.php
@@ -9,8 +9,8 @@
 use function array_key_exists;
 use function is_string;
 
-/** @immutable */
-final class RemoteAddr implements Source
+/** @psalm-immutable */
+final readonly class RemoteAddr implements Source
 {
     private const SERVER_PARAM_NAME = 'REMOTE_ADDR';
 
diff --git a/src/Storageless/Http/ClientFingerprint/SameOriginRequest.php b/src/Storageless/Http/ClientFingerprint/SameOriginRequest.php
index b371d6ba..bf5cb6b6 100644
--- a/src/Storageless/Http/ClientFingerprint/SameOriginRequest.php
+++ b/src/Storageless/Http/ClientFingerprint/SameOriginRequest.php
@@ -22,19 +22,19 @@
 /**
  * @internal
  *
- * @immutable
+ * @psalm-immutable
  */
-final class SameOriginRequest implements Constraint
+final readonly class SameOriginRequest implements Constraint
 {
     public const CLAIM = 'fp';
 
     /** @var list<Source> */
-    private readonly array $sources;
+    private array $sources;
     /** @var non-empty-string */
-    private readonly string $currentRequestFingerprint;
+    private string $currentRequestFingerprint;
 
     public function __construct(
-        private readonly Configuration $configuration,
+        private Configuration $configuration,
         ServerRequestInterface $serverRequest,
     ) {
         $this->sources = $this->configuration->sources();
diff --git a/src/Storageless/Http/ClientFingerprint/UserAgent.php b/src/Storageless/Http/ClientFingerprint/UserAgent.php
index 5463b62e..2009a97c 100644
--- a/src/Storageless/Http/ClientFingerprint/UserAgent.php
+++ b/src/Storageless/Http/ClientFingerprint/UserAgent.php
@@ -6,8 +6,8 @@
 
 use Psr\Http\Message\ServerRequestInterface;
 
-/** @immutable */
-final class UserAgent implements Source
+/** @psalm-immutable */
+final readonly class UserAgent implements Source
 {
     public function extractFrom(ServerRequestInterface $request): string
     {
diff --git a/src/Storageless/Http/Configuration.php b/src/Storageless/Http/Configuration.php
index e88468b3..abd64ff3 100644
--- a/src/Storageless/Http/Configuration.php
+++ b/src/Storageless/Http/Configuration.php
@@ -27,7 +27,7 @@
 use Lcobucci\JWT\Configuration as JwtConfig;
 use PSR7Sessions\Storageless\Http\ClientFingerprint\Configuration as FingerprintConfig;
 
-/** @immutable */
+/** @psalm-immutable */
 final class Configuration
 {
     private JwtConfig $jwtConfiguration;
diff --git a/src/Storageless/Http/SessionMiddleware.php b/src/Storageless/Http/SessionMiddleware.php
index e7240984..a01d0afd 100644
--- a/src/Storageless/Http/SessionMiddleware.php
+++ b/src/Storageless/Http/SessionMiddleware.php
@@ -43,14 +43,14 @@
 
 use function sprintf;
 
-/** @immutable */
-final class SessionMiddleware implements MiddlewareInterface
+/** @psalm-immutable */
+final readonly class SessionMiddleware implements MiddlewareInterface
 {
     public const SESSION_CLAIM     = 'session-data';
     public const SESSION_ATTRIBUTE = 'session';
 
     public function __construct(
-        private readonly Configuration $config,
+        private Configuration $config,
     ) {
     }