Oxygen OS Stock Messenger

I just recently purchased the One Plus 2 and was messing around with the settings, I am a paragraph texter and I noticed that compared to my OPO the size of the text in the messenger is much much larger. Is there any way to change this? I looked through all the settings and I even have nova launcher but I can't find anywhere to change the size of the text in the stock text messaging app. It's terribly unsightly so I'd like for there to be a fix. Thanks in advance.