Index: sys/net/bpf.c
===================================================================
RCS file: /cvs/src/sys/net/bpf.c,v
retrieving revision 1.177
diff -u -p -r1.177 bpf.c
--- sys/net/bpf.c	13 Jun 2019 21:14:53 -0000	1.177
+++ sys/net/bpf.c	10 Sep 2019 23:59:14 -0000
@@ -1367,7 +1367,7 @@ bpf_mtap(caddr_t arg, const struct mbuf 
  * it or keep a pointer to it.
  */
 int
-bpf_mtap_hdr(caddr_t arg, caddr_t data, u_int dlen, const struct mbuf *m,
+bpf_mtap_hdr(caddr_t arg, const void *data, u_int dlen, const struct mbuf *m,
     u_int direction, void (*cpfn)(const void *, void *, size_t))
 {
 	struct m_hdr mh;
@@ -1377,7 +1377,7 @@ bpf_mtap_hdr(caddr_t arg, caddr_t data, 
 		mh.mh_flags = 0;
 		mh.mh_next = (struct mbuf *)m;
 		mh.mh_len = dlen;
-		mh.mh_data = data;
+		mh.mh_data = (void *)data;
 		m0 = (struct mbuf *)&mh;
 	} else 
 		m0 = m;
Index: sys/net/bpf.h
===================================================================
RCS file: /cvs/src/sys/net/bpf.h,v
retrieving revision 1.66
diff -u -p -r1.66 bpf.h
--- sys/net/bpf.h	17 Mar 2019 23:57:12 -0000	1.66
+++ sys/net/bpf.h	10 Sep 2019 23:59:14 -0000
@@ -315,7 +315,7 @@ struct mbuf;
 
 int	 bpf_validate(struct bpf_insn *, int);
 int	 bpf_mtap(caddr_t, const struct mbuf *, u_int);
-int	 bpf_mtap_hdr(caddr_t, caddr_t, u_int, const struct mbuf *, u_int,
+int	 bpf_mtap_hdr(caddr_t, const void *, u_int, const struct mbuf *, u_int,
 	    void (*)(const void *, void *, size_t));
 int	 bpf_mtap_af(caddr_t, u_int32_t, const struct mbuf *, u_int);
 int	 bpf_mtap_ether(caddr_t, const struct mbuf *, u_int);
Index: share/man/man9/bpf_mtap.9
===================================================================
RCS file: /cvs/src/share/man/man9/bpf_mtap.9,v
retrieving revision 1.14
diff -u -p -r1.14 bpf_mtap.9
--- share/man/man9/bpf_mtap.9	2 Feb 2018 10:52:44 -0000	1.14
+++ share/man/man9/bpf_mtap.9	10 Sep 2019 23:59:14 -0000
@@ -66,7 +66,7 @@
 .Ft int
 .Fo bpf_mtap_hdr
 .Fa "caddr_t bpf"
-.Fa "caddr_t hdr"
+.Fa "const void *hdr"
 .Fa "u_int hdrlen"
 .Fa "const struct mbuf *m"
 .Fa "u_int direction"