diff --git a/src/Communication/Request.php b/src/Communication/Request.php
index f0b0710..e8c1dab 100644
--- a/src/Communication/Request.php
+++ b/src/Communication/Request.php
@@ -11,7 +11,7 @@
  */
 class Request extends Message implements RequestInterface
 {
-    protected ?string $requestId = null;
+    protected string $requestId;
 
     /**
      * Request constructor.
@@ -32,4 +32,4 @@ public function getRequestId(): string
     {
         return $this->requestId;
     }
-}
\ No newline at end of file
+}