Sum of positive from an array of numbers

This is an exercise from CodeWars.

You get an array of numbers, return the sum of all of the positives ones.

Example [1,-4,7,12] => 1 + 7 + 12 = 20

Note: if there is nothing to sum, the sum is default to 0.

Here's my simple solution using Linq.

using System;
using System.Linq;

public class Kata
{
  public static int PositiveSum(int[] arr)
  {
    return arr.Where(x => x > 0).Sum();
  }
}