diff --git a/src/CheckerCommand.php b/src/CheckerCommand.php
index 86941eb..aa82d51 100644
--- a/src/CheckerCommand.php
+++ b/src/CheckerCommand.php
@@ -45,6 +45,11 @@ class CheckerCommand extends Command
      */
     protected $exclude = [];
 
+    /**
+     * @var array
+     */
+    protected $files = [];
+
     /**
      * @var OutputInterface
      */
@@ -112,7 +117,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         if (!\is_null($exclude)) {
             $this->exclude = \array_map('trim', \explode(',', $exclude));
         }
-        
+
         // Set up files:
         if (!\is_null($files)) {
             $this->files = \array_map('trim', \explode(',', $files));
@@ -265,7 +270,7 @@ protected function processDirectory(string $path = '', array &$workList = []): v
             }
         }
     }
-    
+
     /**
      * Iterate through the files and check them out
      *