diff --git a/moo/lib/moo-utl.h b/moo/lib/moo-utl.h
index 4cd862f..7a2378b 100644
--- a/moo/lib/moo-utl.h
+++ b/moo/lib/moo-utl.h
@@ -89,6 +89,33 @@
 } while(0);
 */
 
+
+
+#define MOO_CONST_SWAP16(x) \
+	((qse_uint16_t)((((qse_uint16_t)(x) & (qse_uint16_t)0x00ffU) << 8) | \
+	                (((qse_uint16_t)(x) & (qse_uint16_t)0xff00U) >> 8) ))
+
+#define MOO_CONST_SWAP32(x) \
+	((qse_uint32_t)((((qse_uint32_t)(x) & (qse_uint32_t)0x000000ffUL) << 24) | \
+	                (((qse_uint32_t)(x) & (qse_uint32_t)0x0000ff00UL) <<  8) | \
+	                (((qse_uint32_t)(x) & (qse_uint32_t)0x00ff0000UL) >>  8) | \
+	                (((qse_uint32_t)(x) & (qse_uint32_t)0xff000000UL) >> 24) ))
+
+#if defined(MOO_ENDIAN_LITTLE)
+#       define MOO_CONST_NTOH16(x) MOO_CONST_SWAP16(x)
+#       define MOO_CONST_HTON16(x) MOO_CONST_SWAP16(x)
+#       define MOO_CONST_NTOH32(x) MOO_CONST_SWAP32(x)
+#       define MOO_CONST_HTON32(x) MOO_CONST_SWAP32(x)
+#elif defined(MOO_ENDIAN_BIG)
+#       define MOO_CONST_NTOH16(x) (x)
+#       define MOO_CONST_HTON16(x) (x)
+#       define MOO_CONST_NTOH32(x) (x)
+#       define MOO_CONST_HTON32(x) (x)
+#else
+#       error UNKNOWN ENDIAN
+#endif
+
+
 #if defined(__cplusplus)
 extern "C" {
 #endif
@@ -421,6 +448,50 @@ MOO_EXPORT int moo_ucwidth (
 	moo_uch_t uc
 );
 
+
+/* ------------------------------------------------------------------------- */
+
+#if defined(MOO_HAVE_UINT16_T)
+MOO_EXPORT moo_uint16_t moo_ntoh16 (
+	moo_uint16_t x
+);
+
+MOO_EXPORT moo_uint16_t moo_hton16 (
+	moo_uint16_t x
+);
+#endif
+
+#if defined(MOO_HAVE_UINT32_T)
+MOO_EXPORT moo_uint32_t moo_ntoh32 (
+	moo_uint32_t x
+);
+
+MOO_EXPORT moo_uint32_t moo_hton32 (
+	moo_uint32_t x
+);
+#endif
+
+#if defined(MOO_HAVE_UINT64_T)
+MOO_EXPORT moo_uint64_t moo_ntoh64 (
+	moo_uint64_t x
+);
+
+MOO_EXPORT moo_uint64_t moo_hton64 (
+	moo_uint64_t x
+);
+#endif
+
+#if defined(MOO_HAVE_UINT128_T)
+MOO_EXPORT moo_uint128_t moo_ntoh128 (
+	moo_uint128_t x
+);
+
+MOO_EXPORT moo_uint128_t moo_hton128 (
+	moo_uint128_t x
+);
+#endif
+
+
 #if defined(__cplusplus)
 }
 #endif
diff --git a/moo/lib/utl.c b/moo/lib/utl.c
index 946e640..3c7631b 100644
--- a/moo/lib/utl.c
+++ b/moo/lib/utl.c
@@ -1002,3 +1002,110 @@ moo_uint32_t moo_hton32 (moo_uint32_t x)
 #endif
 }
 #endif
+
+
+#if defined(MOO_HAVE_UINT64_T)
+
+moo_uint64_t moo_ntoh64 (moo_uint64_t x)
+{
+#if defined(MOO_ENDIAN_BIG)
+	return x;
+#elif defined(MOO_ENDIAN_LITTLE)
+	moo_uint8_t* c = (moo_uint8_t*)&x;
+	return (moo_uint64_t)(
+		((moo_uint64_t)c[0] << 56) | 
+		((moo_uint64_t)c[1] << 48) | 
+		((moo_uint64_t)c[2] << 40) |
+		((moo_uint64_t)c[3] << 32) |
+		((moo_uint64_t)c[4] << 24) |
+		((moo_uint64_t)c[5] << 16) |
+		((moo_uint64_t)c[6] << 8)  |
+		((moo_uint64_t)c[7] << 0));
+#else
+#	error Unknown endian
+#endif
+}
+
+moo_uint64_t moo_hton64 (moo_uint64_t x)
+{
+#if defined(MOO_ENDIAN_BIG)
+	return x;
+#elif defined(MOO_ENDIAN_LITTLE)
+	moo_uint8_t* c = (moo_uint8_t*)&x;
+	return (moo_uint64_t)(
+		((moo_uint64_t)c[0] << 56) | 
+		((moo_uint64_t)c[1] << 48) | 
+		((moo_uint64_t)c[2] << 40) |
+		((moo_uint64_t)c[3] << 32) |
+		((moo_uint64_t)c[4] << 24) |
+		((moo_uint64_t)c[5] << 16) |
+		((moo_uint64_t)c[6] << 8)  |
+		((moo_uint64_t)c[7] << 0));
+#else
+#	error Unknown endian
+#endif
+}
+
+#endif
+
+/* --------------------------------------------------------------- */
+
+#if defined(MOO_HAVE_UINT128_T)
+
+moo_uint128_t moo_ntoh128 (moo_uint128_t x)
+{
+#if defined(MOO_ENDIAN_BIG)
+	return x;
+#elif defined(MOO_ENDIAN_LITTLE)
+	moo_uint8_t* c = (moo_uint8_t*)&x;
+	return (moo_uint128_t)(
+		((moo_uint128_t)c[0]  << 120) | 
+		((moo_uint128_t)c[1]  << 112) | 
+		((moo_uint128_t)c[2]  << 104) |
+		((moo_uint128_t)c[3]  << 96) |
+		((moo_uint128_t)c[4]  << 88) |
+		((moo_uint128_t)c[5]  << 80) |
+		((moo_uint128_t)c[6]  << 72) |
+		((moo_uint128_t)c[7]  << 64) |
+		((moo_uint128_t)c[8]  << 56) | 
+		((moo_uint128_t)c[9]  << 48) | 
+		((moo_uint128_t)c[10] << 40) |
+		((moo_uint128_t)c[11] << 32) |
+		((moo_uint128_t)c[12] << 24) |
+		((moo_uint128_t)c[13] << 16) |
+		((moo_uint128_t)c[14] << 8)  |
+		((moo_uint128_t)c[15] << 0));
+#else
+#	error Unknown endian
+#endif
+}
+
+moo_uint128_t moo_hton128 (moo_uint128_t x)
+{
+#if defined(MOO_ENDIAN_BIG)
+	return x;
+#elif defined(MOO_ENDIAN_LITTLE)
+	moo_uint8_t* c = (moo_uint8_t*)&x;
+	return (moo_uint128_t)(
+		((moo_uint128_t)c[0]  << 120) | 
+		((moo_uint128_t)c[1]  << 112) | 
+		((moo_uint128_t)c[2]  << 104) |
+		((moo_uint128_t)c[3]  << 96) |
+		((moo_uint128_t)c[4]  << 88) |
+		((moo_uint128_t)c[5]  << 80) |
+		((moo_uint128_t)c[6]  << 72) |
+		((moo_uint128_t)c[7]  << 64) |
+		((moo_uint128_t)c[8]  << 56) | 
+		((moo_uint128_t)c[9]  << 48) | 
+		((moo_uint128_t)c[10] << 40) |
+		((moo_uint128_t)c[11] << 32) |
+		((moo_uint128_t)c[12] << 24) |
+		((moo_uint128_t)c[13] << 16) |
+		((moo_uint128_t)c[14] << 8)  |
+		((moo_uint128_t)c[15] << 0));
+#else
+#	error Unknown endian
+#endif
+}
+
+#endif