diff --git a/src/sha.h b/src/sha.h
index e3af7b4..ddf5cf1 100644
--- a/src/sha.h
+++ b/src/sha.h
@@ -72,7 +72,7 @@ inline word16 ByteReverse(word16 value)
 
 inline word32 ByteReverse(word32 value)
 {
-#if defined(__GNUC__)
+#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
     __asm__ ("bswap %0" : "=r" (value) : "0" (value));
     return value;
 #elif defined(CRYPTOPP_BYTESWAP_AVAILABLE)