This current (as are all laws on the Juice) Alabama law is just flat-out weird. Here it is.
Section 30-1-3 – Issue of incestuous marriages not deemed illegitimate.
The issue of any incestuous marriage, before the same is annulled, shall not be deemed illegitimate.
(Code 1852, §1945; Code 1867, §2334; Code 1876, §2673; Code 1886, §2310; Code 1896, §2840; Code 1907, §4880; Code 1923, §8994; Code 1940, T. 34, §3.)