diff --git a/endian.h b/endian.h
index fe2d6fc..0d178df 100644
--- a/endian.h
+++ b/endian.h
@@ -22,7 +22,9 @@
 
 #if defined(__linux__) || defined(__CYGWIN__)
 
-#	include <endian.h>
+#	undef PORTABLE_ENDIAN_H__
+#	include_next <endian.h>
+#	define PORTABLE_ENDIAN_H__
 
 #elif defined(__APPLE__)
 
@@ -48,11 +50,11 @@
 #	define __LITTLE_ENDIAN LITTLE_ENDIAN
 #	define __PDP_ENDIAN    PDP_ENDIAN
 
-#elif defined(__OpenBSD__)
+#elif defined(__OpenBSD__) || defined(__FreeBSD__)
 
 #	include <sys/endian.h>
 
-#elif defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
+#elif defined(__NetBSD__) || defined(__DragonFly__)
 
 #	include <sys/endian.h>
 
@@ -72,19 +74,19 @@
 
 #	if BYTE_ORDER == LITTLE_ENDIAN
 
-#		define htobe16(x) htons(x)
+#		define htobe16(x) __builtin_bswap16(x)
 #		define htole16(x) (x)
-#		define be16toh(x) ntohs(x)
+#		define be16toh(x) __builtin_bswap16(x)
 #		define le16toh(x) (x)
 
-#		define htobe32(x) htonl(x)
+#		define htobe32(x) __builtin_bswap32(x)
 #		define htole32(x) (x)
-#		define be32toh(x) ntohl(x)
+#		define be32toh(x) __builtin_bswap32(x)
 #		define le32toh(x) (x)
 
-#		define htobe64(x) htonll(x)
+#		define htobe64(x) __builtin_bswap64(x)
 #		define htole64(x) (x)
-#		define be64toh(x) ntohll(x)
+#		define be64toh(x) __builtin_bswap64(x)
 #		define le64toh(x) (x)
 
 #	elif BYTE_ORDER == BIG_ENDIAN