diff --git a/src/Command.php b/src/Command.php
index a3bfe11..2c5278f 100644
--- a/src/Command.php
+++ b/src/Command.php
@@ -19,10 +19,13 @@ class Command
     /** @var callable $handler The handler */
     private $handler;
 
-    public function __construct(string $name, callable $handler)
+    private ?array $signature;
+
+    public function __construct(string $name, callable $handler, ?array $signature = null)
     {
         $this->name = $name;
         $this->handler = $handler;
+        $this->signature = $signature;
     }
 
     public function getName(): string
@@ -66,5 +69,10 @@ class Command
         return $args;
     }
 
+    public function getSignature(): array
+    {
+        return $this->signature ?? $this->parameters();
+    }
+
 }
 
diff --git a/tests/CommandTest.php b/tests/CommandTest.php
index 54d30f0..f5fe8fe 100644
--- a/tests/CommandTest.php
+++ b/tests/CommandTest.php
@@ -31,8 +31,8 @@ class CommandTest extends \PHPUnit\Framework\TestCase
         $command = new Command("test", function (string $a, ?int $b, bool $c = false) { });
         $expect = [
             'a' => 'string',
-            'b' => 'int',
-            'c' => '?bool'
+            'b' => '?int',
+            'c' => 'bool=false'
         ];
         $this->assertEquals($expect, $command->parameters());
     }