diff --git a/src/libs/compat/freebsd_network/compat/sys/mbuf.h b/src/libs/compat/freebsd_network/compat/sys/mbuf.h
index c6d2d42539..f26227cbc6 100644
--- a/src/libs/compat/freebsd_network/compat/sys/mbuf.h
+++ b/src/libs/compat/freebsd_network/compat/sys/mbuf.h
@@ -129,7 +129,7 @@ void m_extadd(struct mbuf *m, caddr_t buffer, u_int size,
     void (*freeHook)(void *, void *), void *args, int flags, int type);
 
 
-#define mtod(m, type)	(type)((m)->m_data)
+#define mtod(m, type)	((type)((m)->m_data))
 
 #define m_tag_delete(mb, tag) \
 	panic("m_tag_delete unsupported.");
@@ -144,6 +144,7 @@ void m_extadd(struct mbuf *m, caddr_t buffer, u_int size,
 
 extern int max_linkhdr;
 extern int max_protohdr;
+extern int max_hdr;
 
 #include <sys/mbuf-fbsd.h>
 
diff --git a/src/libs/compat/freebsd_network/mbuf.c b/src/libs/compat/freebsd_network/mbuf.c
index 46a8114247..a496ea73ec 100644
--- a/src/libs/compat/freebsd_network/mbuf.c
+++ b/src/libs/compat/freebsd_network/mbuf.c
@@ -25,6 +25,8 @@ static object_cache *sChunkCache;
 int max_linkhdr = 16;
 int max_protohdr = 40 + 20; /* ip6 + tcp */
 
+/* max_linkhdr + max_protohdr, but that's not allowed by gcc. */
+int max_hdr = 16 + 40 + 20;
 
 static int
 m_to_oc_flags(int how)