diff --git a/core/network.h b/core/network.h
index a5f7899bb..a7559ebed 100644
--- a/core/network.h
+++ b/core/network.h
@@ -57,6 +57,7 @@
 #include <sodium.h>
 #else
 #include <crypto_box.h>
+#define crypto_box_MACBYTES (crypto_box_ZEROBYTES - crypto_box_BOXZEROBYTES)
 #endif
 
 #ifdef __cplusplus