diff --git a/src/Runner/Parallel/ParallelisationException.php b/src/Runner/Parallel/ParallelisationException.php
index 28a4b8ab9b7..4b7d2842698 100644
--- a/src/Runner/Parallel/ParallelisationException.php
+++ b/src/Runner/Parallel/ParallelisationException.php
@@ -25,7 +25,7 @@ final class ParallelisationException extends \RuntimeException
 {
     public static function forUnknownIdentifier(ProcessIdentifier $identifier): self
     {
-        return new self('Unknown process identifier: '.(string) $identifier);
+        return new self('Unknown process identifier: '.$identifier->toString());
     }
 
     /**
diff --git a/src/Runner/Parallel/ProcessFactory.php b/src/Runner/Parallel/ProcessFactory.php
index d737b5c3880..64de299f93b 100644
--- a/src/Runner/Parallel/ProcessFactory.php
+++ b/src/Runner/Parallel/ProcessFactory.php
@@ -80,7 +80,7 @@ public function getCommandArgs(int $serverPort, ProcessIdentifier $identifier, R
             '--port',
             (string) $serverPort,
             '--identifier',
-            escapeshellarg((string) $identifier),
+            escapeshellarg($identifier->toString()),
         ];
 
         if ($runnerConfig->isDryRun()) {
diff --git a/src/Runner/Parallel/ProcessIdentifier.php b/src/Runner/Parallel/ProcessIdentifier.php
index 03bb11df433..469c665d582 100644
--- a/src/Runner/Parallel/ProcessIdentifier.php
+++ b/src/Runner/Parallel/ProcessIdentifier.php
@@ -21,7 +21,7 @@
  *
  * @internal
  */
-final class ProcessIdentifier implements \Stringable
+final class ProcessIdentifier
 {
     private const IDENTIFIER_PREFIX = 'php-cs-fixer_parallel_';
 
@@ -32,7 +32,7 @@ private function __construct(string $identifier)
         $this->identifier = $identifier;
     }
 
-    public function __toString(): string
+    public function toString(): string
     {
         return $this->identifier;
     }
diff --git a/src/Runner/Parallel/ProcessPool.php b/src/Runner/Parallel/ProcessPool.php
index d48f9edcd18..ef4bcf3802c 100644
--- a/src/Runner/Parallel/ProcessPool.php
+++ b/src/Runner/Parallel/ProcessPool.php
@@ -45,21 +45,21 @@ public function __construct(ServerInterface $server, ?callable $onServerClose =
 
     public function getProcess(ProcessIdentifier $identifier): Process
     {
-        if (!isset($this->processes[(string) $identifier])) {
+        if (!isset($this->processes[$identifier->toString()])) {
             throw ParallelisationException::forUnknownIdentifier($identifier);
         }
 
-        return $this->processes[(string) $identifier];
+        return $this->processes[$identifier->toString()];
     }
 
     public function addProcess(ProcessIdentifier $identifier, Process $process): void
     {
-        $this->processes[(string) $identifier] = $process;
+        $this->processes[$identifier->toString()] = $process;
     }
 
     public function endProcessIfKnown(ProcessIdentifier $identifier): void
     {
-        if (!isset($this->processes[(string) $identifier])) {
+        if (!isset($this->processes[$identifier->toString()])) {
             return;
         }
 
@@ -77,7 +77,7 @@ private function endProcess(ProcessIdentifier $identifier): void
     {
         $this->getProcess($identifier)->quit();
 
-        unset($this->processes[(string) $identifier]);
+        unset($this->processes[$identifier->toString()]);
 
         if (0 === \count($this->processes)) {
             $this->server->close();
diff --git a/tests/Console/Command/WorkerCommandTest.php b/tests/Console/Command/WorkerCommandTest.php
index 04ade0f6a6f..049a238f062 100644
--- a/tests/Console/Command/WorkerCommandTest.php
+++ b/tests/Console/Command/WorkerCommandTest.php
@@ -59,13 +59,13 @@ public function testMissingPortCausesFailure(): void
         self::expectException(ParallelisationException::class);
         self::expectExceptionMessage('Missing parallelisation options');
 
-        $commandTester = $this->doTestExecute(['--identifier' => (string) ProcessIdentifier::create()]);
+        $commandTester = $this->doTestExecute(['--identifier' => ProcessIdentifier::create()->toString()]);
     }
 
     public function testWorkerCantConnectToServerWhenExecutedDirectly(): void
     {
         $commandTester = $this->doTestExecute([
-            '--identifier' => (string) ProcessIdentifier::create(),
+            '--identifier' => ProcessIdentifier::create()->toString(),
             '--port' => 12_345,
         ]);
 
@@ -107,7 +107,7 @@ public function testWorkerCommunicatesWithTheServer(): void
          * } $workerScope
          */
         $workerScope = [
-            'identifier' => (string) $processIdentifier,
+            'identifier' => $processIdentifier->toString(),
             'messages' => [],
             'connected' => false,
             'chunkRequested' => false,
diff --git a/tests/Runner/Parallel/ProcessFactoryTest.php b/tests/Runner/Parallel/ProcessFactoryTest.php
index 8e561c2e539..32f583f92cc 100644
--- a/tests/Runner/Parallel/ProcessFactoryTest.php
+++ b/tests/Runner/Parallel/ProcessFactoryTest.php
@@ -80,7 +80,7 @@ public function testCreate(array $input, RunnerConfig $config, string $expectedA
             trim(
                 sprintf(
                     'worker --port 1234 --identifier \'%s\' %s',
-                    (string) $identifier,
+                    $identifier->toString(),
                     trim($expectedAdditionalArgs)
                 )
             ),
diff --git a/tests/Runner/Parallel/ProcessIdentifierTest.php b/tests/Runner/Parallel/ProcessIdentifierTest.php
index c3d6450dbad..c90c0951c17 100644
--- a/tests/Runner/Parallel/ProcessIdentifierTest.php
+++ b/tests/Runner/Parallel/ProcessIdentifierTest.php
@@ -29,7 +29,7 @@ public function testCreateIdentifier(): void
     {
         $identifier = ProcessIdentifier::create();
 
-        self::assertStringStartsWith('php-cs-fixer_parallel_', (string) $identifier);
+        self::assertStringStartsWith('php-cs-fixer_parallel_', $identifier->toString());
     }
 
     /**
@@ -42,7 +42,7 @@ public function testFromRaw(string $rawIdentifier, bool $valid): void
         }
 
         $identifier = ProcessIdentifier::fromRaw($rawIdentifier);
-        self::assertSame($rawIdentifier, (string) $identifier);
+        self::assertSame($rawIdentifier, $identifier->toString());
     }
 
     /**