filter with simple regexp (without flag) seems not working

[ballinette]

with version 1.1.3 (kuzzle 1.x)

If I subscribe to a filter with following format:

regexp: {
    message: '^Hello\ '
}

I am notified for any messages, even ones which does not match the regexp.

If I subscribe with a flag, with following format, it works as expected:

regexp: {
    message: {
      value: '^Hello\ ',
      flags: 'i'
    }
}

[scottinet]

I reproduced it ( 😨 )