diff --git a/include/grgsm/endian.h b/include/grgsm/endian.h
index c176a49..231503d 100644
--- a/include/grgsm/endian.h
+++ b/include/grgsm/endian.h
@@ -9,6 +9,7 @@
 #  define htobe16(x) OSSwapHostToBigInt16(x)
 #  define htobe32(x) OSSwapHostToBigInt32(x)
 
+#  define be16toh(x) OSSwapBigToHostInt16(x)
 #  define be32toh(x) OSSwapBigToHostInt32(x)
 #endif