_BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ #define OPENSSL_64_BIT
+ #define OPENSSL_PPC64LE
+-#elif (defined(__PPC64__) || defined(__powerpc64__)) && defined(_BIG_ENDIAN)
++#elif (defined(__PPC64__) || defined(__powerpc64__)) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ #define OPENSSL_64_BIT
+ #define OPENSSL_PPC64BE
+ #define OPENSSL_BIG_ENDIAN
+-#elif (defined(__PPC__) || defined(__powerpc__)) && defined(_BIG_ENDIAN)
++#elif (defined(__PPC__) || defined(__powerpc__)) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ #define OPENSSL_32_BIT
+ #define OPENSSL_PPC32BE
+ #define OPENSSL_BIG_ENDIAN