[GAMEPLAY] Jayce passive tooltip does not match bonus given

I was playing a coop vs ai game and noticed that the tooltip for jayces passive claims he gets 40 movement speed when he uses his ult. I had 400 movespeed when standing around since i had tier two lucidity boots and the speed enchant. When I transformed, my movement speed became 435, even though I would expect it to be 440. I started paying more attention to my MS from then on and the problem persisted through several changes in base MS. Appears to be a tooltip update issue (or ninja Jayce nerf D: )