Serial.println in class in Arduino

I am trying to do Serial.println()inside a class in an Arduino environment. However, the compiler says it has Serialnot been declared in this area. Here is the code:

Code in Menu.h

class Menu
{
    public:
        int options[4];

        void test() {
          Serial.println("here");
        }

    private:

};

The code in the main file:

#include "Menu.h"

Menu menu;

void setup() {
    Serial.begin(9600);
    menu.test();
}

void loop() {
}