simplification error with | and a prefix

[novas0x2a]

$ exrex -sv '^(prefix/1|prefix/23)'
[(AT, AT_BEGINNING), (SUBPATTERN, (1, 0, 0, [(LITERAL, 112), (LITERAL, 114), (LITERAL, 101), (LITERAL, 102), (LITERAL, 105), (LITERAL, 120), (LITERAL, 47), (BRANCH, (None, [[(LITERAL, 49)], [(LITERAL, 50), (LITERAL, 51)]]))]))]
^(prefix/1|23)

$ exrex -sv '^(prefix/1|23)'
[(AT, AT_BEGINNING), (SUBPATTERN, (1, 0, 0, [(BRANCH, (None, [[(LITERAL, 112), (LITERAL, 114), (LITERAL, 101), (LITERAL, 102), (LITERAL, 105), (LITERAL, 120), (LITERAL, 47), (LITERAL, 49)], [(LITERAL, 50), (LITERAL, 51)]]))]))]
^(prefix/1|23)

Looks like it doesn't insert the () necessary to preserve the original logic (I'd probably expect something like ^(prefix/(1|23)) here). Interestingly, if I make the outer group non-capturing, it corrects the issue:

$ exrex -sv '^(?:prefix/1|prefix/23)'
[(AT, AT_BEGINNING), (LITERAL, 112), (LITERAL, 114), (LITERAL, 101), (LITERAL, 102), (LITERAL, 105), (LITERAL, 120), (LITERAL, 47), (BRANCH, (None, [[(LITERAL, 49)], [(LITERAL, 50), (LITERAL, 51)]]))]
^prefix/(?:1|23)

Otherwise, thanks for the great lib!