diff --git a/composer.json b/composer.json
index 42c1e6b..453b609 100644
--- a/composer.json
+++ b/composer.json
@@ -5,6 +5,7 @@
         }
     },
     "require": {
-        "symfony/console": "^4.2"
+        "symfony/console": "^4.2",
+        "symfony/process": "^4.2"
     }
 }
diff --git a/src/Deblan/Command/CheckCommand.php b/src/Deblan/Command/CheckCommand.php
index 6a55db2..03ff634 100644
--- a/src/Deblan/Command/CheckCommand.php
+++ b/src/Deblan/Command/CheckCommand.php
@@ -7,6 +7,7 @@ use Symfony\Component\Console\Output\OutputInterface;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Command\Command as BaseCommand;
 use Symfony\Component\Console\Helper\Table;
+use Symfony\Component\Process\Process;
 
 /**
  * class CheckCommand.
@@ -83,7 +84,16 @@ class CheckCommand extends BaseCommand
 
     protected function check($domain)
     {
-        $whois = shell_exec(sprintf('whois %s', escapeshellarg($domain)));
+        $process = new Process(['whois', $domain]);
+        $process->run();
+
+        if (!$process->isSuccessful()) {
+            $this->fails[] = [$domain, 'FAIL'];
+
+            return;
+        }
+
+        $whois = $process->getOutput();
 
         preg_match('/Expiry Date: ([^\s]+)/i', $whois, $match);