diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index f5ba9abf6379..ce00553f0ff5 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -1333,7 +1333,7 @@ nospace:
 #endif
 
 struct mbuf *
-m_uiotombuf(struct uio *uio, int how, int len)
+m_uiotombuf(struct uio *uio, int how, int len, int align)
 {
 	struct mbuf *m_new = NULL, *m_final = NULL;
 	int progress = 0, error = 0, length, total;
@@ -1342,12 +1342,15 @@ m_uiotombuf(struct uio *uio, int how, int len)
 		total = min(uio->uio_resid, len);
 	else
 		total = uio->uio_resid;
-	if (total > MHLEN)
+	if (align >= MHLEN)
+		goto nospace;
+	if (total + align > MHLEN)
 		m_final = m_getcl(how, MT_DATA, M_PKTHDR);
 	else
 		m_final = m_gethdr(how, MT_DATA);
 	if (m_final == NULL)
 		goto nospace;
+	m_final->m_data += align;
 	m_new = m_final;
 	while (progress < total) {
 		length = total - progress;
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index f4a4b1682ea1..2f59d87ba155 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -1796,7 +1796,7 @@ do_sendfile(struct thread *td, struct sendfile_args *uap, int compat)
 			hdr_uio->uio_td = td;
 			hdr_uio->uio_rw = UIO_WRITE;
 			if (hdr_uio->uio_resid > 0) {
-				m_header = m_uiotombuf(hdr_uio, M_DONTWAIT, 0);
+				m_header = m_uiotombuf(hdr_uio, M_DONTWAIT, 0, 0);
 				if (m_header == NULL)
 					goto done;
 				headersize = m_header->m_pkthdr.len;
diff --git a/sys/net/if_tap.c b/sys/net/if_tap.c
index cc07baf776ea..2f7474b57bb9 100644
--- a/sys/net/if_tap.c
+++ b/sys/net/if_tap.c
@@ -827,7 +827,7 @@ tapwrite(dev, uio, flag)
 		return (EIO);
 	}
 
-	if ((m = m_uiotombuf(uio, M_DONTWAIT, 0)) == NULL) {
+	if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, ETHER_ALIGN)) == NULL) {
 		ifp->if_ierrors ++;
 		return (error);
 	}
diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index 6fe7b10c96b3..cd209cb411d9 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -761,7 +761,7 @@ tunwrite(struct cdev *dev, struct uio *uio, int flag)
 		return (EIO);
 	}
 
-	if ((m = m_uiotombuf(uio, M_DONTWAIT, 0)) == NULL) {
+	if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0)) == NULL) {
 		ifp->if_ierrors++;
 		return (error);
 	}
diff --git a/sys/netgraph/ng_device.c b/sys/netgraph/ng_device.c
index df6ee4cc2718..9439a574f209 100644
--- a/sys/netgraph/ng_device.c
+++ b/sys/netgraph/ng_device.c
@@ -466,7 +466,7 @@ ngdwrite(struct cdev *dev, struct uio *uio, int flag)
 	if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
 		return (EIO);
 
-	if ((m = m_uiotombuf(uio, M_DONTWAIT, 0)) == NULL)
+	if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0)) == NULL)
 		return (ENOBUFS);
 
 	NG_SEND_DATA_ONLY(error, priv->hook, m);
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index a3d2a61aa391..c514e0fb2f5d 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -582,7 +582,7 @@ void		 m_print(const struct mbuf *, int);
 struct	mbuf	*m_pulldown(struct mbuf *, int, int, int *);
 struct	mbuf	*m_pullup(struct mbuf *, int);
 struct	mbuf	*m_split(struct mbuf *, int, int);
-struct	mbuf	*m_uiotombuf(struct uio *, int, int);
+struct	mbuf	*m_uiotombuf(struct uio *, int, int, int);
 
 /*-
  * Network packets may have annotations attached by affixing a list