Index: src/sha.h
--- src/sha.h.orig
+++ src/sha.h
@@ -8,6 +8,7 @@
 #ifndef __LIBSTROPHE_SHA_H__
 #define __LIBSTROPHE_SHA_H__
 
+#include <endian.h>
 #include <string.h>
 
 #ifdef __cplusplus
@@ -19,7 +20,9 @@ extern "C" {
 
 #if defined(__BIG_ENDIAN__) ||                                   \
     (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
-     __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+     __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) || \
+    (defined(BYTE_ORDER) && defined(BIG_ENDIAN) && \
+     BYTE_ORDER == BIG_ENDIAN)
 
 #define STORE32H(x, y)      \
     do {                    \
@@ -46,7 +49,9 @@ extern "C" {
 
 #elif defined(__LITTLE_ENDIAN__) ||                                 \
     (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
-     __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+     __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) || \
+    (defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && \
+     BYTE_ORDER == LITTLE_ENDIAN)
 
 #define STORE32H(x, y)                         \
     do {                                       \