@ -676,7 +676,7 @@ class Request implements \ArrayAccess, \Countable, IRequest {
* @return string HTTP protocol. HTTP/2, HTTP/1.1 or HTTP/1.0.
*/
public function getHttpProtocol(): string {
$claimedProtocol = $this->server['SERVER_PROTOCOL'];
$claimedProtocol = $this->server['SERVER_PROTOCOL'] ?? '';
if (\is_string($claimedProtocol)) {
$claimedProtocol = strtoupper($claimedProtocol);