diff --git a/miner.h b/miner.h
index a74740f6..3a65d755 100644
--- a/miner.h
+++ b/miner.h
@@ -145,7 +145,7 @@ static inline int fsync (int fd)
 # if __BYTE_ORDER == __LITTLE_ENDIAN
 #  define be32toh(x) bswap_32(x)
 #  define htobe32(x) bswap_32(x)
-#  define htobe64(x) bswap_32(x)
+#  define htobe64(x) bswap_64(x)
 # elif __BYTE_ORDER == __BIG_ENDIAN
 #  define be32toh(x) (x)
 #  define htobe32(x) (x)