diff --git a/src/include/ipxe/netdevice.h b/src/include/ipxe/netdevice.h
index 0daa1d62..d0e628a4 100644
--- a/src/include/ipxe/netdevice.h
+++ b/src/include/ipxe/netdevice.h
@@ -44,7 +44,7 @@ struct device;
 #define MAX_LL_HEADER_LEN 36
 
 /** Maximum length of a network-layer address */
-#define MAX_NET_ADDR_LEN 4
+#define MAX_NET_ADDR_LEN 16
 
 /** Maximum length of a network-layer header
  *