Enclitics and Stress

Where does the stress fall in a word with an enclitic attached? Does it remain where it would be without the enclitic, or do normal stress rules apply to determine the stress? That is, which of the following is correct?

habébimusne - stress not changed by the enclitic
habebimúsne - using the normal stress rules

I’m most interested in the classical period pronunciation, and how it should be read in prose. I assume funny stuff happens in poetry, but this isn’t of interest to me because I’m still very much a beginner!

It’s pronounced habebimúsne // sonitur.
The enclitic attracts the accent. // Attrahit accentum encliticum.

Vide hoc:

Excellent, thank you! My next question was going to be about the case of a short vowel such as in deaque, but you beat me to it.

It’s a moot point but I would say follow A&G. Then at least you have the supportive evidence of the ancient grammarians.
Disputatur res. Ut grammaticam de A&G sequaris, dicam. Tunc argumenta saltem grammaticorum antiquorum probantia habeas.