Laravel Routing fails because of # in variable

I got a route like this:

Route::get('/id/{did}', function ($did) {
    echo $did;
});

The variable $did contains a serialnumber like this "1705SN#A5F"

When I return $did I only get 1705SN. How can I change this behavior?

I'm running laravel 5.4

Greetings da.eXecutoR

via da.eXecutoR