diff --git a/src/add-ons/kernel/network/protocols/ipv4/ipv4.c b/src/add-ons/kernel/network/protocols/ipv4/ipv4.c
index e8e69fde6a..a8bb11ca93 100644
--- a/src/add-ons/kernel/network/protocols/ipv4/ipv4.c
+++ b/src/add-ons/kernel/network/protocols/ipv4/ipv4.c
@@ -151,7 +151,7 @@ static struct mbuf *ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phle
 		n->m_next = m;
 		m = n;
 		m->m_len = optlen + sizeof(struct ip);
-		m->m_data += max_linkhdr;
+		m->m_data += get_max_linkhdr();
 		memcpy(mtod(m, void *), ip, sizeof(struct ip));
 	} else {
 		m->m_data -= optlen;
@@ -965,7 +965,7 @@ static int ipv4_output(struct mbuf *m0, struct mbuf *opt, struct route *ro,
 				ipstat.ips_odropped++;
 				goto sendorfree;
 			}
-			m->m_data += max_linkhdr;
+			m->m_data += get_max_linkhdr();
 			mhip = mtod(m, struct ip*);
 			*mhip = *ip;
 			if (hlen > sizeof(struct ip)) {
diff --git a/src/add-ons/kernel/network/protocols/tcp/tcp.c b/src/add-ons/kernel/network/protocols/tcp/tcp.c
index bbe680af60..817b1253e5 100644
--- a/src/add-ons/kernel/network/protocols/tcp/tcp.c
+++ b/src/add-ons/kernel/network/protocols/tcp/tcp.c
@@ -73,8 +73,8 @@ void tcp_init(void)
 	tcp_iss = 1;
 	
 	tcb.inp_next = tcb.inp_prev = &tcb;
-	if (max_protohdr < sizeof(struct tcpiphdr))
-		max_protohdr = sizeof(struct tcpiphdr);
+	if (get_max_protohdr() < sizeof(struct tcpiphdr))
+		set_max_protohdr(sizeof(struct tcpiphdr));
 	memset(&tcpstat, 0, sizeof(struct tcpstat));
 		
 	memset(proto, 0, sizeof(struct protosw *) * IPPROTO_MAX);
@@ -238,7 +238,7 @@ void tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
 		if (!m)
 			return;
 		tlen = 0;
-		m->m_data += max_linkhdr;
+		m->m_data += get_max_linkhdr();
 		*mtod(m, struct tcpiphdr*) = *ti;
 		ti = mtod(m, struct tcpiphdr*);
 		flags = TH_ACK;
diff --git a/src/add-ons/kernel/network/protocols/tcp/tcp_output.c b/src/add-ons/kernel/network/protocols/tcp/tcp_output.c
index 15549f0386..5af7e8a8eb 100644
--- a/src/add-ons/kernel/network/protocols/tcp/tcp_output.c
+++ b/src/add-ons/kernel/network/protocols/tcp/tcp_output.c
@@ -315,9 +315,9 @@ send:
 			error = ENOBUFS;
 			goto out;
 		}
-		m->m_data += max_linkhdr;
+		m->m_data += get_max_linkhdr();
 		m->m_len = hdrlen;
-		if (len <= MHLEN - hdrlen - max_linkhdr) {
+		if (len <= MHLEN - hdrlen - get_max_linkhdr()) {
 			m_copydata(so->so_snd.sb_mb, off, (int)len, mtod(m, caddr_t) + hdrlen);
 			m->m_len += len;
 		} else {
@@ -343,7 +343,7 @@ send:
 			error = ENOBUFS;
 			goto out;
 		}
-		m->m_data += max_linkhdr;
+		m->m_data += get_max_linkhdr();
 		m->m_len = hdrlen;
 	}
 	m->m_pkthdr.rcvif = NULL;