diff --git a/src/Command/ListCommand.php b/src/Command/ListCommand.php
index 3b1eae0..3836b67 100644
--- a/src/Command/ListCommand.php
+++ b/src/Command/ListCommand.php
@@ -3,12 +3,13 @@
 namespace PrivatePackagist\VendorDataExporter\Command;
 
 use PrivatePackagist\ApiClient\Client as PackagistApiClient;
+use PrivatePackagist\VendorDataExporter\Exceptions\MissingApiCredentialsException;
 use PrivatePackagist\VendorDataExporter\Formatter\Manager;
 use PrivatePackagist\VendorDataExporter\Formatter\ManagerInterface;
 use PrivatePackagist\VendorDataExporter\Model;
 use Symfony\Component\Console\Command\Command;
-use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\OutputInterface;
 
 /**
@@ -16,7 +17,7 @@
  * @phpstan-import-type PackageShape from Model\Package
  * @phpstan-import-type VersionShape from Model\Version
  */
-class ListCommand extends Command
+final class ListCommand extends Command
 {
     public const DEFAULT_COMMAND_NAME = 'list';
 
@@ -73,10 +74,10 @@ private function getPackagistApiClient(InputInterface $input): PackagistApiClien
         }
 
         if (!is_string($token = $input->getOption('token'))) {
-            $token = $_ENV['PACKAGIST_API_TOKEN'] ?? throw new \InvalidArgumentException('Missing API credentials: provide API token via command flag or environment variable.');
+            $token = $_ENV['PACKAGIST_API_TOKEN'] ?? throw MissingApiCredentialsException::missingApiToken();
         }
         if (!is_string($secret = $input->getOption('secret'))) {
-            $secret = $_ENV['PACKAGIST_API_SECRET'] ?? throw new \InvalidArgumentException('Missing API credentials: provide API secret via command flag or environment variable.');
+            $secret = $_ENV['PACKAGIST_API_SECRET'] ?? throw MissingApiCredentialsException::missingApiSecret();
         }
 
         $this->packagistApiClient = new PackagistApiClient(null, $_ENV['PACKAGIST_API_URL'] ?? null);
diff --git a/src/Exceptions/MissingApiCredentialsException.php b/src/Exceptions/MissingApiCredentialsException.php
new file mode 100644
index 0000000..cf3648a
--- /dev/null
+++ b/src/Exceptions/MissingApiCredentialsException.php
@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PrivatePackagist\VendorDataExporter\Exceptions;
+
+use InvalidArgumentException;
+
+final class MissingApiCredentialsException extends InvalidArgumentException
+{
+    public static function missingApiToken(): self
+    {
+        return new self('Missing API credentials: provide API token via command flag or environment variable.');
+    }
+
+    public static function missingApiSecret(): self
+    {
+        return new self('Missing API credentials: provide API secret via command flag or environment variable.');
+    }
+}
diff --git a/tests/Command/ListCommandTest.php b/tests/Command/ListCommandTest.php
index 4ca5813..5ad02cf 100644
--- a/tests/Command/ListCommandTest.php
+++ b/tests/Command/ListCommandTest.php
@@ -40,7 +40,7 @@ public function testTextOutput(): void
         $this->command->run($input, $output);
 
         static::assertCount(49, $this->httpClient->getRequests());
-        static::assertSame(file_get_contents(__DIR__ . '/../res/output/output.txt'), $output->fetch());
+        static::assertStringEqualsFile(__DIR__ . '/../res/output/output.txt', $output->fetch());
     }
 
     public function testJsonOutput(): void
@@ -51,7 +51,7 @@ public function testJsonOutput(): void
         $this->command->run($input, $output);
 
         static::assertCount(49, $this->httpClient->getRequests());
-        static::assertSame(file_get_contents(__DIR__ . '/../res/output/output.json'), $output->fetch());
+        static::assertStringEqualsFile(__DIR__ . '/../res/output/output.json', $output->fetch());
     }
 
     public function testCsvOutput(): void
@@ -62,6 +62,6 @@ public function testCsvOutput(): void
         $this->command->run($input, $output);
 
         static::assertCount(49, $this->httpClient->getRequests());
-        static::assertSame(file_get_contents(__DIR__ . '/../res/output/output.csv'), $output->fetch());
+        static::assertStringEqualsFile(__DIR__ . '/../res/output/output.csv', $output->fetch());
     }
 }