symfony: Symfony4: Route not found with path param with a dot

Q	A
Bug report?	yes
Feature request?	no
BC Break report?	yes
RFC?	yes/no
Symfony version	4.0.3

I have notice that {_format} placeholder avoid that routes matches with dots:

/**
 * @Route("/report/{paysheet}")
 *
 * @param $paysheet
 * @return JsonResponse
*/

When I make a request with this path below /report/5a29775c880fc0.79633949 I have this response:

The requested resource /report/5a29775c880fc0.79633949 was not found on this server.

Notice that path param is a uniqid("", true)

I even tryed to add in the requirements section a regular expression to catch that dot without any success.