Make laravel use custom column prefix

I've a column named people_id instead of user_id, so when I run my query in laravel it throws this error

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'user_id' in 'field list' (SQL: insert into `questions` (`user_id`, `created_at`) values (2, 2016-10-19 07:07:33))

How can I make it use people_id instead of user_id, assuming name of table is 'people'

My App/User.php file

<?php
namespace App;
use Illuminate\Foundation\Auth\User as Authenticatable;
class User extends Authenticatable
{
    protected $table='people';
    protected $fillable = [
        'name', 'email', 'password','age'
    ];
    protected $hidden = [
        'password', 'remember_token',
    ];
    public function questions() {
        return $this->hasMany('App\questions');
    }
}

via Chebli Mohamed