diff --git a/src/HeadersPropagator.php b/src/HeadersPropagator.php
index f7aa407..423990e 100644
--- a/src/HeadersPropagator.php
+++ b/src/HeadersPropagator.php
@@ -24,6 +24,7 @@ public static function instance(): self
     public function keys($carrier): array
     {
         assert($carrier instanceof Request);
+
         /** @psalm-suppress InvalidReturnStatement */
         return $carrier->headers->keys();
     }