Minotaur Monk are your horns considered Monk weapons for the benefit of Martial Arts die increase?

While playing a Minotaur Monk are your horns considered Monk weapons for the benefit of Martial Arts die increase? @ChrisPerkinsDnD @mikemearls @JeremyECrawford @matthewmercer

— William (@Hayate_Masaru) June 11, 2018

The monk's Martial Arts feature defines which weapons count as monk weapons (PH, 78). If a weapon isn't included in that definition, that weapon isn't a monk weapon, unless another rule makes an explicit exception. #DnD https://t.co/Cdmfmdbmuw

— Jeremy Crawford (@JeremyECrawford) June 11, 2018