diff --git a/lib/capnp_c.h b/lib/capnp_c.h
index 900bfc3..38ae389 100644
--- a/lib/capnp_c.h
+++ b/lib/capnp_c.h
@@ -13,6 +13,7 @@
 
 #include <stdint.h>
 #include <stdio.h>
+#include <endian.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -299,30 +300,48 @@ CAPN_INLINE uint8_t capn_flip8(uint8_t v) {
 	return v;
 }
 CAPN_INLINE uint16_t capn_flip16(uint16_t v) {
-	union { uint16_t u; uint8_t v[2]; } s;
-	s.v[0] = (uint8_t)v;
-	s.v[1] = (uint8_t)(v>>8);
-	return s.u;
+#if __BYTE_ORDER == __BIG_ENDIAN
+		union { uint16_t u; uint8_t v[2]; } s;
+		s.v[0] = (uint8_t)v;
+		s.v[1] = (uint8_t)(v>>8);
+		return s.u;
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+		return v;
+#else
+#error "Unable to determine endianess ";
+#endif
 }
 CAPN_INLINE uint32_t capn_flip32(uint32_t v) {
-	union { uint32_t u; uint8_t v[4]; } s;
-	s.v[0] = (uint8_t)v;
-	s.v[1] = (uint8_t)(v>>8);
-	s.v[2] = (uint8_t)(v>>16);
-	s.v[3] = (uint8_t)(v>>24);
-	return s.u;
+#if __BYTE_ORDER == __BIG_ENDIAN
+		union { uint32_t u; uint8_t v[4]; } s;
+		s.v[0] = (uint8_t)v;
+		s.v[1] = (uint8_t)(v>>8);
+		s.v[2] = (uint8_t)(v>>16);
+		s.v[3] = (uint8_t)(v>>24);
+		return s.u;
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+		return v;
+#else
+#error "Unable to determine endianess ";
+#endif
 }
 CAPN_INLINE uint64_t capn_flip64(uint64_t v) {
-	union { uint64_t u; uint8_t v[8]; } s;
-	s.v[0] = (uint8_t)v;
-	s.v[1] = (uint8_t)(v>>8);
-	s.v[2] = (uint8_t)(v>>16);
-	s.v[3] = (uint8_t)(v>>24);
-	s.v[4] = (uint8_t)(v>>32);
-	s.v[5] = (uint8_t)(v>>40);
-	s.v[6] = (uint8_t)(v>>48);
-	s.v[7] = (uint8_t)(v>>56);
-	return s.u;
+#if __BYTE_ORDER == __BIG_ENDIAN
+		union { uint64_t u; uint8_t v[8]; } s;
+			s.v[0] = (uint8_t)v;
+			s.v[1] = (uint8_t)(v>>8);
+			s.v[2] = (uint8_t)(v>>16);
+			s.v[3] = (uint8_t)(v>>24);
+			s.v[4] = (uint8_t)(v>>32);
+			s.v[5] = (uint8_t)(v>>40);
+			s.v[6] = (uint8_t)(v>>48);
+			s.v[7] = (uint8_t)(v>>56);
+			return s.u;
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+		return v;
+#else
+#error "Unable to determine endianess ";
+#endif
 }
 
 CAPN_INLINE int capn_write1(capn_ptr p, int off, int val) {