Lichess Elo Rating

I just played a game VS an opponent with the exact same rating as me! (we both were 1634)

Lo and behold, game is a draw!
He gains +1 and I gain -1 rating!!!

Now I'm 1633 !!!

Explain these shenanigans !!!!

Lichess calculates ratings to 2 decimal points it seems - maybe the ratings were different.

Also maybe Lichess didn't like the idea of blending kittens.

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

1633.97 to be exact.