diff --git a/sbin/ping6/ping6.c b/sbin/ping6/ping6.c
index 03381e03431..7e1719ae515 100644
--- a/sbin/ping6/ping6.c
+++ b/sbin/ping6/ping6.c
@@ -863,7 +863,7 @@ main(int argc, char *argv[])
 
 	/* set IP6 packet options */
 	if (ip6optlen) {
-		if ((scmsg = (char *)malloc(ip6optlen)) == 0)
+		if ((scmsg = (char *)malloc(ip6optlen)) == NULL)
 			errx(1, "can't allocate enough memory");
 		smsghdr.msg_control = (caddr_t)scmsg;
 		smsghdr.msg_controllen = ip6optlen;