fizzBuzz откуда берутся undefined?

const fizzBuzz = num => {
   for (let i = 1; i <= num; i++) {
      if (num % 3 === 0 && num % 5 === 0) {
        return console.log('fizzbuzz');
      } else if (num % 5 === 0) {
        return console.log('buzz');
      } else if (num % 3 === 0) {
        return console.log('fizz');
      }
   }
   return num;
};


console.log(fizzBuzz(1));
console.log(fizzBuzz(15));
console.log(fizzBuzz(-25));
console.log(fizzBuzz(60));
console.log(fizzBuzz(3));