braided brake lines

[izanagi]

Hi all,
Just bought a set of braided brake lines for my AE86.
The nipple that goes in the rear caliper seems to be the good one but the other nipple that screw with the copper line from the axle seems to be not correct.
Of course it's a female type but inside it's inverted flare (concave) and the end of the copper line that come from the rear axle is also inverted flare (concave).
In my mind, inverted flare against inverted flare will not work. Aim I right and do I need an adapter to convert it into male 3AN (convex) to do flare into inverted flare ?? or is it OK inverted flare against inverted flare ?

Sorry for my bad English I'm from Belgium

Thanks for your help.