.Fn "size_t strlen" "const char *s"\r
.\"\r
.Pp\r
-.Sy #define _PDCLIB_POSIX_MIN(2008098L) || _PDCLIB_XOPEN_MIN(0)\r
+.Sy #define _XOPEN_SOURCE || _POSIX_C_SOURCE >= 200809L\r
.br\r
.Fn "char *strdup" "const char*src"\r
.\"\r
.Pp\r
-.Sy #define _PDCLIB_POSIX_MIN(2008098L)\r
+.Sy #define _POSIX_C_SOURCE >= 200809L\r
.br\r
.Fn "char *strndup" "const char*src" "size_t n"\r
.\"\r