Python if statement not executing as expected

I have this piece of code:

import bge
import GameLogic
import os

os.system("cls")
scene = GameLogic.getCurrentScene()
objects = scene.objects
objectCube = objects["Cube"]
visible = objectCube.visible
if visible == True:
    objectCube.setVisible(False, True)
else:
    objectCube.setVisible(True, True)

This code is supposed to toggle the visibility of an object but instead the object disappears and immediately reappears in a split second. It looks as if it just flickers. What am I doing wrong?

Also, don't worry about the other variables, they work fine. I have tested them using some Console outputs.