--- tests/bn_isqrt.c.orig Mon Aug 15 10:40:29 2022 +++ tests/bn_isqrt.c Mon Aug 15 10:41:46 2022 @@ -304,6 +304,7 @@ main(int argc, char *argv[]) int ch; int failed = 0, print = 0; +#ifndef _MSC_VER while ((ch = getopt(argc, argv, "C")) != -1) { switch (ch) { case 'C': @@ -314,6 +315,7 @@ main(int argc, char *argv[]) break; } } +#endif if (print) return check_tables(1);