Laravel File validation rule "Required" not working

So the title says all, other rules like "mimes" are works, but I can submit form without file upload. Ofcourse I can use "required" attr in HTML, but I don't want to.

Controller

$rules = [
    'img.*' => 'required|mimes:png,jpeg,jpg',
    ];

$customMessages = [
    'img.required' => 'Yo, what should I call you?',
    ];

$this->validate($request, $rules, $customMessages);

View

<div class="form-group">

    <label for="img">File input</label>
    <input  type="file" class="form-control-file" id="img" value="" name="img[]">
    <small class="text-danger"></small>

</div>

I have other inputs, but with type="text" and their "required" rule works fine. Whats wrong with type="file"? Can't find the answer...

via Chebli Mohamed