diff --git a/composer.json b/composer.json
index bf6021ba..6b82ae93 100644
--- a/composer.json
+++ b/composer.json
@@ -67,8 +67,8 @@
         "ext-sodium": "*",
         "ekino/phpstan-banned-code": "^1.0",
         "ergebnis/phpunit-slow-test-detector": "^2.14",
-        "infection/infection": "^0.28|^0.29",
-        "matthiasnoback/symfony-config-test": "dev-phpunit-11",
+        "infection/infection": "^0.29",
+        "matthiasnoback/symfony-config-test": "5.1.x-dev",
         "paragonie/sodium_compat": "^1.20|^2.0",
         "php-parallel-lint/php-parallel-lint": "^1.3",
         "phpbench/phpbench": "^1.2",
@@ -86,7 +86,7 @@
         "spomky-labs/aes-key-wrap": "^7.0",
         "staabm/phpstan-dba": "^0.2.79",
         "staabm/phpstan-todo-by": "^0.1.25",
-        "struggle-for-php/sfp-phpstan-psr-log": "^0.20.0 || ^0.21.0",
+        "struggle-for-php/sfp-phpstan-psr-log": "^0.20|^0.21",
         "symfony/browser-kit": "^7.0",
         "symfony/http-client": "^7.0",
         "symfony/clock": "^7.0",
@@ -118,11 +118,5 @@
             "php-http/discovery": true,
             "infection/extension-installer": false
         }
-    },
-    "repositories": {
-        "wickedOne_SymfonyConfigTest": {
-            "type": "vcs",
-            "url": "git@github.com:wickedOne/SymfonyConfigTest.git"
-        }
     }
 }
diff --git a/src/Library/Core/Util/ECKey.php b/src/Library/Core/Util/ECKey.php
index 8f50b48e..38ecf545 100644
--- a/src/Library/Core/Util/ECKey.php
+++ b/src/Library/Core/Util/ECKey.php
@@ -11,7 +11,6 @@
 use function is_array;
 use function is_string;
 use const OPENSSL_KEYTYPE_EC;
-use const PHP_EOL;
 use const STR_PAD_LEFT;
 
 /**
@@ -38,10 +37,10 @@ public static function convertPublicKeyToPEM(JWK $jwk): string
             default => throw new InvalidArgumentException('Unsupported curve.'),
         };
         $der .= self::getKey($jwk);
-        $pem = '-----BEGIN PUBLIC KEY-----' . PHP_EOL;
-        $pem .= chunk_split(base64_encode($der), 64, PHP_EOL);
+        $pem = '-----BEGIN PUBLIC KEY-----' . "\n";
+        $pem .= chunk_split(base64_encode($der), 64, "\n");
 
-        return $pem . ('-----END PUBLIC KEY-----' . PHP_EOL);
+        return $pem . ('-----END PUBLIC KEY-----' . "\n");
     }
 
     public static function convertPrivateKeyToPEM(JWK $jwk): string
@@ -54,10 +53,10 @@ public static function convertPrivateKeyToPEM(JWK $jwk): string
             default => throw new InvalidArgumentException('Unsupported curve.'),
         };
         $der .= self::getKey($jwk);
-        $pem = '-----BEGIN EC PRIVATE KEY-----' . PHP_EOL;
-        $pem .= chunk_split(base64_encode($der), 64, PHP_EOL);
+        $pem = '-----BEGIN EC PRIVATE KEY-----' . "\n";
+        $pem .= chunk_split(base64_encode($der), 64, "\n");
 
-        return $pem . ('-----END EC PRIVATE KEY-----' . PHP_EOL);
+        return $pem . ('-----END EC PRIVATE KEY-----' . "\n");
     }
 
     /**
diff --git a/src/Library/KeyManagement/KeyConverter/KeyConverter.php b/src/Library/KeyManagement/KeyConverter/KeyConverter.php
index 6227d2ef..55d8305e 100644
--- a/src/Library/KeyManagement/KeyConverter/KeyConverter.php
+++ b/src/Library/KeyManagement/KeyConverter/KeyConverter.php
@@ -28,7 +28,6 @@
 use const OPENSSL_KEYTYPE_EC;
 use const OPENSSL_KEYTYPE_RSA;
 use const OPENSSL_RAW_DATA;
-use const PHP_EOL;
 use const PREG_PATTERN_ORDER;
 
 /**
@@ -163,11 +162,11 @@ public static function loadFromX5C(array $x5c): array
             throw new InvalidArgumentException('The certificate chain is empty');
         }
         foreach ($x5c as $id => $cert) {
-            assert(is_string($cert), 'Invalid certificate');
-            $x5c[$id] = '-----BEGIN CERTIFICATE-----' . PHP_EOL . chunk_split(
+            assert(is_string($cert), 'Invalid certificate chain');
+            $x5c[$id] = '-----BEGIN CERTIFICATE-----' . "\n" . chunk_split(
                 $cert,
                 64,
-                PHP_EOL
+                "\n"
             ) . '-----END CERTIFICATE-----';
             $x509 = openssl_x509_read($x5c[$id]);
             if ($x509 === false) {
@@ -403,9 +402,9 @@ private static function sanitizePEM(string &$pem): void
 
         $ciphertext = preg_replace('#-.*-|\r|\n| #', '', $pem);
 
-        $pem = $matches[0][0] . PHP_EOL;
-        $pem .= chunk_split($ciphertext ?? '', 64, PHP_EOL);
-        $pem .= $matches[0][1] . PHP_EOL;
+        $pem = $matches[0][0] . "\n";
+        $pem .= chunk_split($ciphertext ?? '', 64, "\n");
+        $pem .= $matches[0][1] . "\n";
     }
 
     /**
@@ -436,16 +435,16 @@ private static function decodePem(string $pem, array $matches, ?string $password
             throw new InvalidArgumentException('Unable to load the key');
         }
 
-        $pem = $result[0][0] . PHP_EOL;
+        $pem = $result[0][0] . "\n";
         $pem .= chunk_split(base64_encode($decoded), 64);
 
-        return $pem . ($result[0][1] . PHP_EOL);
+        return $pem . ($result[0][1] . "\n");
     }
 
     private static function convertDerToPem(string $der_data): string
     {
-        $pem = chunk_split(base64_encode($der_data), 64, PHP_EOL);
+        $pem = chunk_split(base64_encode($der_data), 64, "\n");
 
-        return '-----BEGIN CERTIFICATE-----' . PHP_EOL . $pem . '-----END CERTIFICATE-----' . PHP_EOL;
+        return '-----BEGIN CERTIFICATE-----' . "\n" . $pem . '-----END CERTIFICATE-----' . "\n";
     }
 }
diff --git a/src/Library/KeyManagement/X5UFactory.php b/src/Library/KeyManagement/X5UFactory.php
index 495e79a5..74831cd7 100644
--- a/src/Library/KeyManagement/X5UFactory.php
+++ b/src/Library/KeyManagement/X5UFactory.php
@@ -12,7 +12,6 @@
 use function assert;
 use function is_array;
 use function is_string;
-use const PHP_EOL;
 
 class X5UFactory extends UrlKeySetFactory
 {
@@ -33,7 +32,7 @@ public function loadFromUrl(string $url, array $header = []): JWKSet
         foreach ($data as $kid => $cert) {
             assert(is_string($cert), 'Invalid content.');
             if (mb_strpos($cert, '-----BEGIN CERTIFICATE-----') === false) {
-                $cert = '-----BEGIN CERTIFICATE-----' . PHP_EOL . $cert . PHP_EOL . '-----END CERTIFICATE-----';
+                $cert = '-----BEGIN CERTIFICATE-----' . "\n" . $cert . "\n" . '-----END CERTIFICATE-----';
             }
             $jwk = KeyConverter::loadKeyFromCertificate($cert);
             if (is_string($kid)) {