Physics overlap check running function when there is no overlap

[marros1812]

I have a bit of code, 

game.physics.arcade.overlap(Player, collisionLayer3, climb);function climb() {    Player.body.velocity.y = - 150;}

Now the way I would expect this to work is when the player is overlapping with the collisionLayer3 the function should run however as soon as the game starts the functions runs even though there is no overlap, any ideas?