diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -628,8 +628,8 @@
 	uio.uio_iovcnt = 1;
 	uio.uio_offset = 0;
 	uio.uio_rw = UIO_READ;
-	error = m_unmappedtouio(m, off, &uio, len);
-	KASSERT(error == 0, ("m_unmappedtouio failed: off %d, len %d", off,
+	error = m_unmapped_uiomove(m, off, &uio, len);
+	KASSERT(error == 0, ("m_unmapped_uiomove failed: off %d, len %d", off,
 	   len));
 }
 
@@ -1157,8 +1157,8 @@
 	uio.uio_iovcnt = 1;
 	uio.uio_offset = 0;
 	uio.uio_rw = UIO_WRITE;
-	error = m_unmappedtouio(m, off, &uio, len);
-	KASSERT(error == 0, ("m_unmappedtouio failed: off %d, len %d", off,
+	error = m_unmapped_uiomove(m, off, &uio, len);
+	KASSERT(error == 0, ("m_unmapped_uiomove failed: off %d, len %d", off,
 	   len));
 }
 
@@ -1899,7 +1899,7 @@
  * Copy data to/from an unmapped mbuf into a uio limited by len if set.
  */
 int
-m_unmappedtouio(const struct mbuf *m, int m_off, struct uio *uio, int len)
+m_unmapped_uiomove(const struct mbuf *m, int m_off, struct uio *uio, int len)
 {
 	vm_page_t pg;
 	int error, i, off, pglen, pgoff, seglen, segoff;
@@ -1970,7 +1970,7 @@
 		length = min(m->m_len, total - progress);
 
 		if ((m->m_flags & M_EXTPG) != 0)
-			error = m_unmappedtouio(m, 0, uio, length);
+			error = m_unmapped_uiomove(m, 0, uio, length);
 		else
 			error = uiomove(mtod(m, void *), length, uio);
 		if (error)
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -2198,7 +2198,8 @@
 			SBLASTMBUFCHK(&so->so_rcv);
 			SOCKBUF_UNLOCK(&so->so_rcv);
 			if ((m->m_flags & M_EXTPG) != 0)
-				error = m_unmappedtouio(m, moff, uio, (int)len);
+				error = m_unmapped_uiomove(m, moff, uio,
+				    (int)len);
 			else
 				error = uiomove(mtod(m, char *) + moff,
 				    (int)len, uio);
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -833,7 +833,6 @@
 struct mbuf	*m_getptr(struct mbuf *, int, int *);
 u_int		 m_length(struct mbuf *, struct mbuf **);
 int		 m_mbuftouio(struct uio *, const struct mbuf *, int);
-int		 m_unmappedtouio(const struct mbuf *, int, struct uio *, int);
 void		 m_move_pkthdr(struct mbuf *, struct mbuf *);
 int		 m_pkthdr_init(struct mbuf *, int);
 struct mbuf	*m_prepend(struct mbuf *, int, int);
@@ -843,6 +842,8 @@
 int		 m_sanity(struct mbuf *, int);
 struct mbuf	*m_split(struct mbuf *, int, int);
 struct mbuf	*m_uiotombuf(struct uio *, int, int, int, int);
+int		 m_unmapped_uiomove(const struct mbuf *, int, struct uio *,
+		    int);
 struct mbuf	*m_unshare(struct mbuf *, int);
 int		 m_snd_tag_alloc(struct ifnet *,
 		    union if_snd_tag_alloc_params *, struct m_snd_tag **);