diff --git a/sys/net/firewire.h b/sys/net/firewire.h
--- a/sys/net/firewire.h
+++ b/sys/net/firewire.h
@@ -131,7 +131,7 @@
 	uint16_t		fc_node;	/* our nodeid */
 	struct fw_reass_list	fc_frags;	/* partial datagrams */
 };
-#define	IFP2FWC(ifp)	((struct fw_com *)(ifp)->if_l2com)
+#define	IFP2FWC(ifp)	((struct fw_com *)if_getl2com(ifp))
 
 extern	void	firewire_input(struct ifnet *ifp, struct mbuf *m, uint16_t src);
 extern	void	firewire_ifattach(struct ifnet *, struct fw_hwaddr *);
diff --git a/sys/net/if.c b/sys/net/if.c
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -4941,6 +4941,12 @@
 	return (ifp->if_pcp);
 }
 
+void *
+if_getl2com(if_t ifp)
+{
+	return (ifp->if_l2com);
+}
+
 #ifdef DDB
 static void
 if_show_ifnet(struct ifnet *ifp)
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -644,6 +644,7 @@
 void if_setmaclabel(if_t ifp, struct label *label);
 struct bpf_if *if_getbpf(if_t ifp);
 uint8_t if_getpcp(if_t ifp);
+void *if_getl2com(if_t ifp);
 struct ifvlantrunk *if_getvlantrunk(if_t ifp);
 void *if_getafdata(if_t ifp, int);