diff --git a/.php_cs.dist b/.php_cs.dist
index c123702..dddebf6 100644
--- a/.php_cs.dist
+++ b/.php_cs.dist
@@ -12,9 +12,7 @@ return PhpCsFixer\Config::create()
     [
       '@PSR2' => true,
       '@PHP70Migration' => true,
-      '@PHP70Migration:risky' => true,
       '@PHP71Migration' => true,
-      '@PHP71Migration:risky' => true,
       'header_comment' => ['header' => $header],
       'ordered_class_elements' => true,
       'ordered_imports' => true,
diff --git a/composer.json b/composer.json
index d43d6e3..17c46cf 100644
--- a/composer.json
+++ b/composer.json
@@ -3,7 +3,7 @@
     "description": "Generates dummy mac addresses",
     "type": "library",
     "require": {
-        "php": ">=7.3",
+        "php": "^8.0",
         "ext-json": "*",
         "ext-sodium": "*"
     },
@@ -16,7 +16,7 @@
         "friendsofphp/php-cs-fixer": "^2.18",
         "phpunit/phpunit": "^9.5",
         "squizlabs/php_codesniffer": "^3.5",
-        "symfony/console": "^4.4|^5.0"
+        "symfony/console": "^5.2"
     },
     "autoload-dev": {
       "psr-4": {
diff --git a/src/GenerateMac/Command/GenerateMacCommand.php b/src/GenerateMac/Command/GenerateMacCommand.php
index f24ad4d..2cc7687 100644
--- a/src/GenerateMac/Command/GenerateMacCommand.php
+++ b/src/GenerateMac/Command/GenerateMacCommand.php
@@ -34,16 +34,20 @@ use Symfony\Component\Console\Style\SymfonyStyle;
 
 class GenerateMacCommand extends Command
 {
+    private const SEPARATOR_NAMES = [
+        'colon',
+        'dash',
+        'none',
+    ];
+
     public function configure(): void
     {
         $this
           ->setName('generate-mac')
           ->addOption('count', 'c', InputOption::VALUE_REQUIRED, 'Generate {count} mac addresses.')
-          ->addOption('output', 'o', InputOption::VALUE_REQUIRED, 'Output in this format instead of a string. [json,plain,string]')
-          ->addOption('separator', 's', InputOption::VALUE_REQUIRED, 'The separator to use for mac addresses.')
+          ->addOption('output', 'o', InputOption::VALUE_REQUIRED, 'Output in this format instead of a string. [json, plain, string]')
+          ->addOption('separator', 's', InputOption::VALUE_REQUIRED, 'The separator to use for mac addresses. [colon, dash, none]')
         ;
-
-        parent::configure();
     }
 
     /**
@@ -61,9 +65,9 @@ class GenerateMacCommand extends Command
             throw new RuntimeException('$count should be a positive number greater than zero.');
         }
 
-        $separator = strtolower($input->getOption('separator') ?? 'colon');
+        $separatorName = strtolower($input->getOption('separator') ?? 'colon');
 
-        if (!\in_array($separator, ['colon','none','dash'], true)) {
+        if (!\in_array($separatorName, self::SEPARATOR_NAMES, true)) {
             throw new InvalidArgumentException('Separator must be one of "colon", "none", or "dash"');
         }
 
@@ -71,23 +75,21 @@ class GenerateMacCommand extends Command
 
         $io = new SymfonyStyle($input, $output);
 
-        switch ($separator) {
-            case 'colon':
-            default:
-                $separator = Mac::SEPARATOR_COLON;
-                break;
-            case 'none':
-                $separator = Mac::SEPARATOR_NONE;
-                break;
-            case 'dash':
-                $separator = Mac::SEPARATOR_DASH;
-                break;
-        }
+        $separator = match($separatorName) {
+            'colon' => Mac::SEPARATOR_COLON,
+            'dash' => Mac::SEPARATOR_DASH,
+            'none' => Mac::SEPARATOR_NONE,
+            default => Mac::SEPARATOR_COLON,
+        };
 
         $mac = new Mac($separator);
 
         $macAddresses = $mac->getMacAddresses($count);
 
+        if(empty($macAddresses)) {
+            return Command::FAILURE;
+        }
+
         switch ($outputFormat) {
             case 'string':
             default:
@@ -102,6 +104,6 @@ class GenerateMacCommand extends Command
                 break;
         }
 
-        return 0;
+        return Command::SUCCESS;
     }
 }
diff --git a/src/GenerateMac/Mac.php b/src/GenerateMac/Mac.php
index cef9a0e..ea77d7c 100644
--- a/src/GenerateMac/Mac.php
+++ b/src/GenerateMac/Mac.php
@@ -24,6 +24,7 @@ class Mac
     public const SEPARATOR_COLON = 0;
     public const SEPARATOR_DASH = 1;
     public const SEPARATOR_NONE = 2;
+
     /**
      * Private mac address prefixes that are used
      * internally or with virtual machines and containers.
@@ -68,22 +69,10 @@ class Mac
     protected $isTest = false;
 
     /**
-     * @var int  The mac address separator, can be self::SEPARATOR_*
-     */
-    private $separator;
-
-    /**
-     * @var bool  If we care if we get an already used prefix or not.
-     */
-    private $unique;
-
-    /**
-     * Mac constructor.
-     *
      * @param int $separator  The mac address separator, one of self::SEPARATOR_*
      * @param bool $unique  Whether or not we care if we get a non unique prefix.
      */
-    public function __construct(int $separator = self::SEPARATOR_COLON, bool $unique = true)
+    public function __construct(private int $separator = self::SEPARATOR_COLON, private bool $unique = true)
     {
         $this->setUnique($unique);
         $this->setSeparator($separator);
@@ -196,16 +185,12 @@ class Mac
      */
     public function getSeparatorAsString(): string
     {
-
-        switch ($this->getSeparator()) {
-            default:
-            case self::SEPARATOR_COLON:
-                return ':';
-            case self::SEPARATOR_DASH:
-                return '-';
-            case self::SEPARATOR_NONE:
-                return '';
-        }
+        return match ( $this->getSeparator() ) {
+                self::SEPARATOR_COLON => ':',
+                self::SEPARATOR_DASH => '-',
+                self::SEPARATOR_NONE => '',
+                default => ':',
+            };
     }
 
     /**
@@ -230,11 +215,11 @@ class Mac
      */
     private function generateString(string $template): string
     {
-        $bytes = sodium_bin2hex(\random_bytes(32));
+        $bytes = \sodium_bin2hex(\random_bytes(32));
 
         while (false !== $pos = \strpos($template, 'x')) {
             $replacement = $bytes[\random_int(0, \strlen($bytes) -1)];
-            $template = substr_replace($template, $replacement, $pos, 1);
+            $template = \substr_replace($template, $replacement, $pos, 1);
         }
 
         return $template;
@@ -259,6 +244,6 @@ class Mac
      */
     private function insertSeparator(string $macAddress): string
     {
-        return implode($this->getSeparatorAsString(), str_split($macAddress, 2));
+        return \implode($this->getSeparatorAsString(), \str_split($macAddress, 2));
     }
 }