diff --git a/src/QrBill.php b/src/QrBill.php
index fbe313c2..6082aacf 100644
--- a/src/QrBill.php
+++ b/src/QrBill.php
@@ -72,7 +72,7 @@ public static function create(): self
         return $qrBill;
     }
 
-    public function getHeader(): Header
+    public function getHeader(): ?Header
     {
         return $this->header;
     }