diff -uNr unace-2.5.orig/source/base/all/all.h unace-2.5/source/base/all/all.h
--- unace-2.5.orig/source/base/all/all.h	2010-08-03 14:22:49.809269706 +0000
+++ unace-2.5/source/base/all/all.h	2010-08-03 14:29:10.189469638 +0000
@@ -61,7 +61,7 @@
 #define put_unaligned(ptr, val) ((void)( *(ptr) = (val) ))
 #endif /* __EMULATE_UNALIGNED__ */
 
-#ifdef __BIG_ENDIAN__
+#if __BYTE_ORDER == __BIG_ENDIAN
 #define ADJUST_ENDIANNESS16(Ptr) {\
   USHORT x = get_unaligned((USHORT*) (Ptr));\
   put_unaligned((USHORT*) (Ptr), x >> 8 | x << 8);\
@@ -78,10 +78,12 @@
   x2 = x2 >> 16 | x2 << 16;\
   put_unaligned(((ULONG*) (Ptr)), (x2&0xff00ff00) >> 8 | (x2&0x00ff00ff) << 8);\
 }
-#else
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
 #define ADJUST_ENDIANNESS16(Ptr) 
 #define ADJUST_ENDIANNESS32(Ptr) 
 #define ADJUST_ENDIANNESS64(Ptr) 
+#else
+#error Please define system endianness
 #endif
 
 #endif