Parse error into guzzlehttp

Hi folks,

I've uploaded D8 to my server throw FTP.
I open website, first screen i've this:

Parse error: syntax error, unexpected '[' in /home/web/dc.vaiso.net/huit/core/vendor/guzzlehttp/streams/src/functions.php on line 195

Don't worry, it's because my test server uses php 5.3.3.
But i suggest to add an alert for dummies.