Compare Vector3 on roblox

So I recently noticed on Roblox, when I tried to compare vector, it throws me an error showing attempt to compare two userdata values

here is my code:

if game.Players.LocalPlayer.Character.HumanoidRootPart.Velocity >= Vector3.new(18, 18, 18) then
-- do something here
end

So what is the proper way to use vector3 to compare X,Y, and Z values?