diff --git a/src/Analyser.php b/src/Analyser.php
index f723d56..3bbfebf 100644
--- a/src/Analyser.php
+++ b/src/Analyser.php
@@ -38,7 +38,7 @@ final class Analyser
     /**
      * @psalm-param list<non-empty-string> $files
      */
-    public function analyse(array $files): Result
+    public function analyse(array $files, bool $debug): Result
     {
         $errors      = [];
         $directories = [];
@@ -48,6 +48,10 @@ public function analyse(array $files): Result
         $linesOfCode = new LinesOfCode(0, 0, 0, 0);
 
         foreach ($files as $file) {
+            if ($debug) {
+                print $file . PHP_EOL;
+            }
+
             $directories[] = dirname($file);
 
             try {
diff --git a/src/CLI/Application.php b/src/CLI/Application.php
index f3a9733..5a2c3e2 100644
--- a/src/CLI/Application.php
+++ b/src/CLI/Application.php
@@ -59,7 +59,7 @@ public function run(array $argv): int
             return 1;
         }
 
-        $result = (new Analyser)->analyse($files);
+        $result = (new Analyser)->analyse($files, $arguments->debug());
 
         print (new TextResultFormatter)->format($result);
 
@@ -87,6 +87,8 @@ private function help(): void
   --exclude <path>  Exclude files with <path> in their path from the analysis
                     (can be given multiple times)
 
+  --debug           Print debugging information
+
 EOT;
     }
 }
diff --git a/src/CLI/Arguments.php b/src/CLI/Arguments.php
index 5ab5619..565f63c 100644
--- a/src/CLI/Arguments.php
+++ b/src/CLI/Arguments.php
@@ -25,6 +25,7 @@ final class Arguments
      * @psalm-var list<non-empty-string>
      */
     private array $exclude;
+    private bool $debug;
     private bool $help;
     private bool $version;
 
@@ -33,11 +34,12 @@ final class Arguments
      * @psalm-param list<non-empty-string> $suffixes
      * @psalm-param list<non-empty-string> $exclude
      */
-    public function __construct(array $directories, array $suffixes, array $exclude, bool $help, bool $version)
+    public function __construct(array $directories, array $suffixes, array $exclude, bool $debug, bool $help, bool $version)
     {
         $this->directories = $directories;
         $this->suffixes    = $suffixes;
         $this->exclude     = $exclude;
+        $this->debug       = $debug;
         $this->help        = $help;
         $this->version     = $version;
     }
@@ -66,6 +68,11 @@ public function exclude(): array
         return $this->exclude;
     }
 
+    public function debug(): bool
+    {
+        return $this->debug;
+    }
+
     public function help(): bool
     {
         return $this->help;
diff --git a/src/CLI/ArgumentsBuilder.php b/src/CLI/ArgumentsBuilder.php
index 89ba18a..ea6d299 100644
--- a/src/CLI/ArgumentsBuilder.php
+++ b/src/CLI/ArgumentsBuilder.php
@@ -29,6 +29,7 @@ public function build(array $argv): Arguments
                 [
                     'suffix=',
                     'exclude=',
+                    'debug',
                     'help',
                     'version',
                 ],
@@ -44,6 +45,7 @@ public function build(array $argv): Arguments
         $directories = $options[1];
         $exclude     = [];
         $suffixes    = ['.php'];
+        $debug       = false;
         $help        = false;
         $version     = false;
 
@@ -59,6 +61,11 @@ public function build(array $argv): Arguments
 
                     break;
 
+                case '--debug':
+                    $debug = true;
+
+                    break;
+
                 case 'h':
                 case '--help':
                     $help = true;
@@ -83,6 +90,7 @@ public function build(array $argv): Arguments
             array_values($directories),
             $suffixes,
             $exclude,
+            $debug,
             $help,
             $version,
         );
diff --git a/tests/end-to-end/help.phpt b/tests/end-to-end/help.phpt
index 59a8146..5fbd01a 100644
--- a/tests/end-to-end/help.phpt
+++ b/tests/end-to-end/help.phpt
@@ -19,3 +19,5 @@ Options for selecting files:
                     (default: .php; can be given multiple times)
   --exclude <path>  Exclude files with <path> in their path from the analysis
                     (can be given multiple times)
+
+  --debug           Print debugging information
diff --git a/tests/unit/AnalyserTest.php b/tests/unit/AnalyserTest.php
index 398cea7..bd7e41d 100644
--- a/tests/unit/AnalyserTest.php
+++ b/tests/unit/AnalyserTest.php
@@ -28,6 +28,7 @@ public function testAnalysesFiles(): void
                 __DIR__ . '/../_fixture/ExampleInterface.php',
                 __DIR__ . '/../_fixture/ExampleTrait.php',
             ],
+            false,
         );
 
         $this->assertFalse($result->hasErrors());