diff --git a/src/Input/InputCollection.php b/src/Input/InputCollection.php
index 525ab44..ddf99ba 100644
--- a/src/Input/InputCollection.php
+++ b/src/Input/InputCollection.php
@@ -77,7 +77,7 @@ class InputCollection
 
     public function getArgumentsByIndex(int $index): ?AbstractInputType
     {
-        return $this->arguments[$index];
+        return $this->arguments[$index] ?? null;
     }
 
     public function getArguments(): array