Strength of the Ages- Incorrect tooltip

In both the mastery page and the in-game tooltip, Strength of the Ages states that a champion gains 20 max health for killing/being near an ally killing large monster kills and 10 max health for siege minion kills. However, in game these values are reversed, with large monsters granting 10 max health and siege minions granting 20 max health. Nothing else about the mastery appears to be out of order, just that the values are the opposite of what is listed in both out of game and in game tooltip.