diff --git a/usr.sbin/ndp/ndp.c b/usr.sbin/ndp/ndp.c
index 570961a3e9f9..17e439ce5844 100644
--- a/usr.sbin/ndp/ndp.c
+++ b/usr.sbin/ndp/ndp.c
@@ -116,7 +116,7 @@
 
 #define NEXTADDR(w, s) \
 	if (rtm->rtm_addrs & (w)) { \
-		bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);}
+		bcopy((char *)&s, cp, sizeof(s)); cp += SA_SIZE(&s);}
 
 
 static pid_t pid;