diff --git a/src/Cookie/ResponseCookie.php b/src/Cookie/ResponseCookie.php
index dedeae8..7cd3126 100644
--- a/src/Cookie/ResponseCookie.php
+++ b/src/Cookie/ResponseCookie.php
@@ -166,7 +166,7 @@ private static function parseDate(string $date): ?\DateTimeImmutable
     public function __construct(
         string $name,
         string $value = '',
-        CookieAttributes $attributes = null
+        ?CookieAttributes $attributes = null
     ) {
         if (!\preg_match('(^[^()<>@,;:\\\"/[\]?={}\x01-\x20\x7F]++$)', $name)) {
             throw new InvalidCookieException("Invalid cookie name: '{$name}'");
diff --git a/src/Http2/Http2Parser.php b/src/Http2/Http2Parser.php
index df4fce9..866da6a 100644
--- a/src/Http2/Http2Parser.php
+++ b/src/Http2/Http2Parser.php
@@ -158,7 +158,7 @@ public function getReceivedFrameCount(): int
         return $this->receivedFrameCount;
     }
 
-    public function parse(string $settings = null): \Generator
+    public function parse(?string $settings = null): \Generator
     {
         if ($settings !== null) {
             $this->parseSettings($settings, \strlen($settings), self::NO_FLAG, 0);