diff --git a/include/gsm/endian.h b/include/gsm/endian.h
new file mode 100644
index 0000000..c176a49
--- /dev/null
+++ b/include/gsm/endian.h
@@ -0,0 +1,15 @@
+#ifndef GSM_ENDIAN_H
+#define GSM_ENDIAN_H
+
+#if defined(__linux__)
+#  include <endian.h>
+#elif defined(__APPLE__)
+#  include <libkern/OSByteOrder.h>
+
+#  define htobe16(x) OSSwapHostToBigInt16(x)
+#  define htobe32(x) OSSwapHostToBigInt32(x)
+
+#  define be32toh(x) OSSwapBigToHostInt32(x)
+#endif
+
+#endif /* GSM_ENDIAN_H */