--- src/boot.c
+++ src/boot.c
@@ -36,6 +36,7 @@
 #include "io.h"
 #include "boot.h"
 #include "check.h"
+#include "conversion.h"
 
 #define ROUND_TO_MULTIPLE(n,m) ((n) && (m) ? (n)+(m)-1-((n)-1)%(m) : 0)
     /* don't divide by zero */
--- src/check.c
+++ src/check.c
@@ -37,6 +37,7 @@
 #include "file.h"
 #include "lfn.h"
 #include "check.h"
+#include "conversion.h"
 
 static DOS_FILE *root;
 
--- src/fat.c
+++ src/fat.c
@@ -34,6 +34,7 @@
 #include "io.h"
 #include "check.h"
 #include "fat.h"
+#include "conversion.h"
 
 /**
  * Fetch the FAT entry for a specified cluster.
--- src/lfn.c
+++ src/lfn.c
@@ -32,6 +32,7 @@
 #include "fsck.fat.h"
 #include "lfn.h"
 #include "file.h"
+#include "conversion.h"
 
 typedef struct {
     uint8_t id;			/* sequence number for slot */
--- src/mkfs.fat.c
+++ src/mkfs.fat.c
@@ -70,6 +70,8 @@
 
 #include "msdos_fs.h"
 
+#include "conversion.h"
+
 /* In earlier versions, an own llseek() was used, but glibc lseek() is
  * sufficient (or even better :) for 64 bit offsets in the meantime */
 #define llseek lseek
--- src/conversion.h
+++ src/conversion.h
@@ -0,0 +1,98 @@
+#ifndef _CONVERSION_H
+#define _CONVERSION_H
+
+
+#ifdef _BSD_SOURCE
+
+# include <endian.h>
+# include <byteswap.h>
+
+# if __BYTE_ORDER == __LITTLE_ENDIAN
+
+#  ifndef htobe16
+#   define htobe16(x) __bswap_16 (x)
+#  endif
+#  ifndef htole16
+#   define htole16(x) (x)
+#  endif
+#  ifndef be16toh
+#   define be16toh(x) __bswap_16 (x)
+#  endif
+#  ifndef le16toh
+#   define le16toh(x) (x)
+#  endif
+
+#  ifndef htobe32
+#   define htobe32(x) __bswap_32 (x)
+#  endif
+#  ifndef htole32
+#   define htole32(x) (x)
+#  endif
+#  ifndef be32toh
+#   define be32toh(x) __bswap_32 (x)
+#  endif
+#  ifndef le32toh
+#   define le32toh(x) (x)
+#  endif
+
+#  ifndef htobe64
+#   define htobe64(x) __bswap_64 (x)
+#  endif
+#  ifndef htole64
+#   define htole64(x) (x)
+#  endif
+#  ifndef be64toh
+#   define be64toh(x) __bswap_64 (x)
+#  endif
+#  ifndef le64toh
+#   define le64toh(x) (x)
+#  endif
+
+# elif __BYTE_ORDER == __BIG_ENDIAN
+
+#  ifndef htobe16
+#   define htobe16(x) (x)
+#  endif
+#  ifndef htole16
+#   define htole16(x) __bswap_16 (x)
+#  endif
+#  ifndef be16toh
+#   define be16toh(x) (x)
+#  endif
+#  ifndef le16toh
+#   define le16toh(x) __bswap_16 (x)
+#  endif
+
+#  ifndef htobe32
+#   define htobe32(x) (x)
+#  endif
+#  ifndef htole32
+#   define htole32(x) __bswap_32 (x)
+#  endif
+#  ifndef be32toh
+#   define be32toh(x) (x)
+#  endif
+#  ifndef le32toh
+#   define le32toh(x) __bswap_32 (x)
+#  endif
+
+#  ifndef htobe64
+#   define htobe64(x) (x)
+#  endif
+#  ifndef htole64
+#   define htole64(x) __bswap_64 (x)
+#  endif
+#  ifndef be64toh
+#   define be64toh(x) (x)
+#  endif
+#  ifndef le64toh
+#   define le64toh(x) __bswap_64 (x)
+#  endif
+
+# else
+#  error unsupported byte order!
+# endif
+
+#endif
+
+#endif