Why does this repeat loop continue beyond it's "until" threshold?

I made an intro GUI that is intended to fade text in and out - to actually make it fade in and out I used a repeat loop. The script looks something like this:

       repeat wait(0.05)
       script.Parent.TextLabel.TextTransparency = script.Parent.TextLabel.TextTransparency - 0.1
       until script.Parent.TextLabel.TextTransparency == 0
end

This isn't the entire script, just an example of how it's set up. I have multiple different elements that are fading in, each on their own repeat loop. All the loops work just fine, except the one showcased above, which is the only one dealing with TextTransparency. The TextTransparency is set to 1 and the loop is supposed to stop when it reaches 0. It does not stop once it reaches 0 and continues into the negatives, putting the rest of the script on hold. The only solution I have is to replace this line

       until script.Parent.TextLabel.TextTransparency == 0

with this

       until script.Parent.TextLabel.TextTransparency >= 0

This works, but it doesn't stop at 0, it stops at -0.

The rest of the script uses the exact same format as the initial code and works as intended, breaking the loop when the transparency or volume of something reaches 0. It is JUST that bit, and I can't figure out why it's so bugged.