diff --git a/getifaddr.c b/getifaddr.c
index 5f95031..2d9474c 100644
--- a/getifaddr.c
+++ b/getifaddr.c
@@ -205,9 +205,13 @@ getsyshwaddr(char *buf, int len)
 				continue;
 			memcpy(mac, ifr.ifr_hwaddr.sa_data, 6);
 #else
+			if (p->ifa_addr->sa_family != AF_LINK)
+				continue;
 			struct sockaddr_dl *sdl;
 			sdl = (struct sockaddr_dl*)p->ifa_addr;
-			memcpy(mac, LLADDR(sdl), sdl->sdl_alen);
+			if (sdl->sdl_alen != 6)
+				continue;
+			memcpy(mac, LLADDR(sdl), 6);
 #endif
 			if (MACADDR_IS_ZERO(mac))
 				continue;