How can I shut off the change in font size via volume rocker?

[AC Question]

I HATE that function. When I'm in a text message and I hit my volume rocker the font gets bigger and smaller. On my S3 and S4 I was able to disable. I cant find how to do it on here to save my life. Its the only function I sincerely hate. thanks!

 

[cardboard60]

settings
quick settings
display
font sizes