Check leaderstats kills of local player?

Hello, i was wondering why this script does not work?

local lock = script.Parent

while true do
	local player = game.Players.LocalPlayer
	if player.leaderstats.Kills.Value >= 30 then
		lock.Visible = false
	end
end

I want it to do "when you have enough kills you unlock a new weapon." but it does not do that. The lock still remains after you hit 30 kills, any help?