diff --git a/CHANGES.md b/CHANGES.md
index 9b8d0fd..5936475 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,26 @@
+## v4.0.0
+
+* Rename the `to/from_bytes` functions to refer to `octets`
+  instead.  This distinguishes the meaning of human-readable
+  addresses (`string`s in this library) and byte-packed
+  representations(`octet`s in this library) from the OCaml
+  `bytes` type that represents mutable strings.
+
+  Porting code should just be a matter of renaming functions
+  such as:
+   - `Ipaddr.of_bytes` becomes `Ipaddr.of_octets`
+   - `Macaddr.to_bytes` becomes `Macaddr.to_octets`
+
+* Introduce new `write_octets` functions that can write
+  octet representations of IPv4/v6 into an existing bytestring.
+
+* Use the `domain-name` library to produce domain names
+  from IP addresses.
+
+* Remove the `ipaddr.sexp` and `macaddr.sexp` ocamlfind
+  subpackages and instead have `ipaddr-sexp` and `macaddr-sexp`
+  to match the opam package names.
+
 ## v3.1.0 (2019-03-02)
 
 * Do not leak a `Not_found` exception when parsing `[:`
diff --git a/lib/ipaddr.ml b/lib/ipaddr.ml
index dc4ec5d..2eb4dfd 100644
--- a/lib/ipaddr.ml
+++ b/lib/ipaddr.ml
@@ -62,7 +62,6 @@ let (>!)  x y = (x >|> y) &&& 0xFF_l
 let (<!)  x y = (x &&& 0xFF_l) <|< y
 
 let need_more x = Parse_error ("not enough data", x)
-let too_much x = Parse_error ("too much data", x)
 
 let char_0 = int_of_char '0'
 let char_a = int_of_char 'a'
@@ -184,35 +183,38 @@ module V4 = struct
   let pp ppf i =
     Format.fprintf ppf "%s" (to_string i)
 
-  (* Byte conversion *)
-
-  let of_bytes_raw bs o =
-    make
-      (Char.code bs.[0 + o])
-      (Char.code bs.[1 + o])
-      (Char.code bs.[2 + o])
-      (Char.code bs.[3 + o])
-
-  let of_bytes_exn bs =
-    let len = String.length bs in
-    if len > 4 then raise (too_much bs);
-    if len < 4 then raise (need_more bs);
-    of_bytes_raw bs 0
-
-  let of_bytes bs = try_with_result of_bytes_exn bs
-
-  let to_bytes_raw i b o =
-    Bytes.set b (0 + o) (Char.chr ((|~) (i >! 24)));
-    Bytes.set b (1 + o) (Char.chr ((|~) (i >! 16)));
-    Bytes.set b (2 + o) (Char.chr ((|~) (i >!  8)));
-    Bytes.set b (3 + o) (Char.chr ((|~) (i >!  0)))
-
-  let to_bytes i =
-    let b = Bytes.create 4 in
-    to_bytes_raw i b 0;
-    Bytes.to_string b
-
-  (* Int32*)
+  (* Octets conversion *)
+
+  let of_octets_exn ?(off=0) bs =
+    try
+      make
+      (Char.code bs.[0 + off])
+      (Char.code bs.[1 + off])
+      (Char.code bs.[2 + off])
+      (Char.code bs.[3 + off])
+    with _ -> raise (need_more bs)
+
+  let of_octets ?off bs = try_with_result (of_octets_exn ?off) bs
+
+  let write_octets_exn ?(off=0) i b =
+    try
+      Bytes.set b (0 + off) (Char.chr ((|~) (i >! 24)));
+      Bytes.set b (1 + off) (Char.chr ((|~) (i >! 16)));
+      Bytes.set b (2 + off) (Char.chr ((|~) (i >!  8)));
+      Bytes.set b (3 + off) (Char.chr ((|~) (i >!  0)))
+    with _ -> raise (need_more (Bytes.to_string b))
+
+  let write_octets ?off i bs = try_with_result (write_octets_exn ?off i) bs
+
+  let to_octets i =
+    String.init 4 (function
+      | 0 -> Char.chr ((|~) (i >! 24))
+      | 1 -> Char.chr ((|~) (i >! 16))
+      | 2 -> Char.chr ((|~) (i >! 8))
+      | 3 -> Char.chr ((|~) (i >! 0))
+      | _ -> assert false)
+
+  (* Int32 *)
   let of_int32 i = i
   let to_int32 i = i
 
@@ -230,7 +232,7 @@ module V4 = struct
     Bytes.set macb 3 (Char.chr ((|~) (i >|> 16 &&& 0x7F_l)));
     Bytes.set macb 4 (Char.chr ((|~) (i >! 8)));
     Bytes.set macb 5 (Char.chr ((|~) (i >! 0)));
-    Macaddr.of_bytes_exn (Bytes.to_string macb)
+    Macaddr.of_octets_exn (Bytes.to_string macb)
 
   (* Host *)
   let to_domain_name i =
@@ -433,21 +435,11 @@ module B128 = struct
     in
     (a,b,c,d,e,f,g,h)
 
-  let to_bytes_raw (a,b,c,d) byte o =
-    V4.to_bytes_raw a byte (o+0);
-    V4.to_bytes_raw b byte (o+4);
-    V4.to_bytes_raw c byte (o+8);
-    V4.to_bytes_raw d byte (o+12)
-
-  let _of_bytes_exn bs = (* TODO : from cstruct *)
-    let len = String.length bs in
-    if len > 16 then raise (too_much bs);
-    if len < 16 then raise (need_more bs);
-    let hihi = V4.of_bytes_raw bs 0 in
-    let hilo = V4.of_bytes_raw bs 4 in
-    let lohi = V4.of_bytes_raw bs 8 in
-    let lolo = V4.of_bytes_raw bs 12 in
-    of_int32 (hihi, hilo, lohi, lolo)
+  let write_octets_exn ?(off=0) (a,b,c,d) byte =
+    V4.write_octets_exn ~off a byte;
+    V4.write_octets_exn ~off:(off+4) b byte;
+    V4.write_octets_exn ~off:(off+8) c byte;
+    V4.write_octets_exn ~off:(off+12) d byte
 
   let compare (a1,b1,c1,d1) (a2,b2,c2,d2) =
     match V4.compare a1 a2 with
@@ -639,25 +631,21 @@ module V6 = struct
 
   (* byte conversion *)
 
-  let of_bytes_raw bs o = (* TODO : from cstruct *)
-    let hihi = V4.of_bytes_raw bs (o + 0) in
-    let hilo = V4.of_bytes_raw bs (o + 4) in
-    let lohi = V4.of_bytes_raw bs (o + 8) in
-    let lolo = V4.of_bytes_raw bs (o + 12) in
+  let of_octets_exn ?(off=0) bs = (* TODO : from cstruct *)
+    let hihi = V4.of_octets_exn ~off bs in
+    let hilo = V4.of_octets_exn ~off:(off+4) bs in
+    let lohi = V4.of_octets_exn ~off:(off+8) bs in
+    let lolo = V4.of_octets_exn ~off:(off+12) bs in
     of_int32 (hihi, hilo, lohi, lolo)
 
-  let of_bytes_exn bs = (* TODO : from cstruct *)
-    let len = String.length bs in
-    if len > 16 then raise (too_much bs);
-    if len < 16 then raise (need_more bs);
-    of_bytes_raw bs 0
+  let of_octets ?off bs = try_with_result (of_octets_exn ?off) bs
 
-  let of_bytes bs = try_with_result of_bytes_exn bs
+  let write_octets ?off i bs = try_with_result (write_octets_exn ?off i) bs
 
-  let to_bytes i =
-    let bs = Bytes.create 16 in
-    to_bytes_raw i bs 0;
-    Bytes.to_string bs
+  let to_octets i =
+    let b = Bytes.create 16 in
+    write_octets_exn i b;
+    Bytes.to_string b
 
   (* MAC *)
   (* {{:https://tools.ietf.org/html/rfc2464#section-7}RFC 2464}. *)
@@ -670,7 +658,7 @@ module V6 = struct
     Bytes.set macb 3 (Char.chr ((|~) (i >! 16)));
     Bytes.set macb 4 (Char.chr ((|~) (i >! 8)));
     Bytes.set macb 5 (Char.chr ((|~) (i >! 0)));
-    Macaddr.of_bytes_exn (Bytes.to_string macb)
+    Macaddr.of_octets_exn (Bytes.to_string macb)
 
   (* Host *)
   let to_domain_name (a,b,c,d) =
@@ -886,7 +874,7 @@ module V6 = struct
   let link_address_of_mac =
     let c b i = Char.code (String.get b i) in
     fun mac ->
-      let bmac = Macaddr.to_bytes mac in
+      let bmac = Macaddr.to_octets mac in
       let c_0 = c bmac 0 lxor 2 in
       let addr = make 0 0 0 0
         (c_0      lsl 8 + c bmac 1)
diff --git a/lib/ipaddr.mli b/lib/ipaddr.mli
index d4c5f5e..2d92a45 100644
--- a/lib/ipaddr.mli
+++ b/lib/ipaddr.mli
@@ -1,4 +1,5 @@
 (*
+ * Copyright (c) 2019 Anil Madhavapeddy <anil@recoil.org>
  * Copyright (c) 2013-2015 David Sheets <sheets@alum.mit.edu>
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -54,20 +55,21 @@ module V4 : sig
   (** Converts the low bytes of four int values into an abstract {! V4.t }. *)
   val make : int -> int -> int -> int -> t
 
-  (** {3 Text string conversion} *)
+  (** {3 Text string conversion}
+      These manipulate human-readable IPv4 addresses (for example [192.168.1.2]). *)
 
-  (** [of_string s] is the address {!t} represented by the IPv4 address [s].
-      Returns a human-readable error string if parsing failed. *)
+  (** [of_string s] is the address {!t} represented by the human-readable IPv4
+      address [s]. Returns a human-readable error string if parsing failed. *)
   val of_string : string -> (t, [> `Msg of string ]) result
 
-  (** [of_string_exn s] is the address {!t} represented
-      by [s]. Raises {!Parse_error} if [s] is not a
-      valid representation of an IPv4 address. *)
+  (** [of_string_exn s] is the address {!t} represented as a human-readable IPv4
+      address [s]. Raises {!Parse_error} if [s] is not exactly 4 bytes long. *)
   val of_string_exn : string -> t
 
   (** [of_string_raw s off] acts as {!of_string_exn} but takes as an extra
       argument the offset into the string for reading. [off] will be
-      mutated to an unspecified value during the function call. *)
+      mutated to an unspecified value during the function call. [s] will
+      a {!Parse_error} exception if it is an invalid or truncated IP address. *)
   val of_string_raw : string -> int ref -> t
 
   (** [to_string ipv4] is the dotted decimal string representation
@@ -82,28 +84,36 @@ module V4 : sig
       the formatter [f]. *)
   val pp : Format.formatter -> t -> unit [@@ocaml.toplevel_printer]
 
-  (** {3 Bytestring conversion} *)
-
-  (** [of_bytes s] is the address {!t} represented by the IPv4 octets
-      represented by [s].  [s] should be exactly 4 bytes long.
-      Returns a human-readable error string if parsing fails. *)
-  val of_bytes : string -> (t, [> `Msg of string ]) result
-
-  (** [of_bytes_exn ipv4_octets] is the address represented
-      by [ipv4_octets]. Raises [Parse_error] if [ipv4_octets] is not a
-      valid representation of an IPv4 address. *)
-  val of_bytes_exn : string -> t
-
-  (** [of_bytes_raw s off] is the same as {!of_bytes_exn} but takes
-      an extra paramenter [off] the offset into the bytes for reading. *)
-  val of_bytes_raw : string -> int -> t
-
-  (** [to_bytes ipv4] is a string of length 4 encoding [ipv4]. *)
-  val to_bytes : t -> string
-
-  (** [to_bytes_raw ipv4 bytes offset] writes the 4 byte encoding of [ipv4]
-      into [bytes] at offset [offset]. *)
-  val to_bytes_raw : t -> Bytes.t -> int -> unit
+  (** {3 Octets conversion}
+      These manipulate IPv4 addresses represented as a sequence of
+      four bytes. (e.g for example [0xc0a80102] will be the representation
+      of the human-readable [192.168.1.2] address. *)
+
+  (** [of_octets ?off s] is the address {!t} represented by the IPv4 octets
+      represented by [s] starting from offset [off] within the string.
+      [s] must be at least [off+4] bytes long.
+      Returns a human-readable error string if parsing fails.
+      [off] defaults to 0. *)
+  val of_octets : ?off:int -> string -> (t, [> `Msg of string ]) result
+
+  (** [of_octets_exn ipv4_octets] is the IPv4 address represented
+      by [ipv4_octets] starting from offset [off] within the string.
+      Raises {!Parse_error} if [ipv4_octets] is not at least [off+4] bytes long. 
+      [off] defaults to 0. *)
+  val of_octets_exn : ?off:int -> string -> t
+
+  (** [write_octets ?off ipv4 b] writes the [ipv4] as octets to [b] starting
+       from offset [off]. [b] must be at least [off+4] long or an error is
+       returned. *)
+  val write_octets : ?off:int -> t -> bytes -> (unit, [> `Msg of string ]) result
+
+  (** [write_octets_exn ?off ipv4 b] writes the [ipv4] as octets to [b] starting
+       from offset [off]. [b] must be at least [off+4] long or a
+       {!Parse_error} is raised. *)
+  val write_octets_exn : ?off:int -> t -> bytes -> unit
+
+  (** [to_octets ipv4] returns the 4 bytes representing the [ipv4] octets. *)
+  val to_octets : t -> string
 
   (** {3 Int conversion} *)
 
@@ -200,7 +210,7 @@ module V4 : sig
     val pp : Format.formatter -> t -> unit [@@ocaml.toplevel_printer]
 
     (** [of_address_string_exn cidr_addr] is the address and prefix
-        represented by [cidr_addr]. Raises [Parse_error] if [cidr_addr] is not
+        represented by [cidr_addr]. Raises {!Parse_error} if [cidr_addr] is not
         a valid representation of a CIDR-scoped address. *)
     val of_address_string_exn : string -> t * addr
 
@@ -310,7 +320,7 @@ module V6 : sig
   (** {3 Text string conversion} *)
 
   (** [of_string_exn ipv6_string] is the address represented
-      by [ipv6_string]. Raises [Parse_error] if [ipv6_string] is not a
+      by [ipv6_string]. Raises {!Parse_error} if [ipv6_string] is not a
       valid representation of an IPv6 address. *)
   val of_string_exn : string -> t
 
@@ -323,7 +333,7 @@ module V6 : sig
   val of_string_raw : string -> int ref -> t
 
   (** [to_string ipv6] is the string representation of [ipv6],
-      i.e. XXX:XX:X::XXX:XX. *)
+      i.e. [XXX:XX:X::XXX:XX]. *)
   val to_string : t -> string
 
   (** [to_buffer buf ipv6] writes the string representation of [ipv6] into the
@@ -334,27 +344,30 @@ module V6 : sig
       the formatter [f]. *)
   val pp : Format.formatter -> t -> unit [@@ocaml.toplevel_printer]
 
-  (** {3 Bytestring conversion} *)
+  (** {3 Octets conversion} *)
 
-  (** [of_bytes_exn ipv6_octets] is the address represented
-      by [ipv6_octets]. Raises [Parse_error] if [ipv6_octets] is not a
-      valid representation of an IPv6 address. *)
-  val of_bytes_exn : string -> t
+  (** [of_octets_exn ?off ipv6_octets] is the address represented
+      by [ipv6_octets], starting from offset [off].
+      Raises {!Parse_error} if [ipv6_octets] is not a valid representation of
+      an IPv6 address. *)
+  val of_octets_exn : ?off:int -> string -> t
 
-  (** Same as {!of_bytes_exn} but returns an result type instead of raising
+  (** Same as {!of_octets_exn} but returns an result type instead of raising
       an exception. *)
-  val of_bytes : string -> (t, [> `Msg of string ]) result
+  val of_octets : ?off:int -> string -> (t, [> `Msg of string ]) result
 
-  (** Same as {!of_bytes_exn} but takes an extra paramenter, the offset into
-      the bytes for reading. *)
-  val of_bytes_raw : string -> int -> t
+  (** [write_octets_exn ?off ipv6 b] writes 16 bytes that encode [ipv6] into [b] starting
+      from offset [off] within [b].  [b] must be at least [off+16] bytes long or
+      a {!Parse_error} exception will be raised. *)
+  val write_octets_exn : ?off:int -> t -> bytes -> unit
 
-  (** [to_bytes ipv6] is a string of length 16 encoding [ipv6]. *)
-  val to_bytes : t -> string
-
-  (** [to_bytes_raw ipv6 bytes offset] writes the 16 bytes encoding of [ipv6]
-      into [bytes] at offset [offset]. *)
-  val to_bytes_raw : t -> Bytes.t -> int -> unit
+  (** [write_octets ?off ipv6 b] writes 16 bytes that encode [ipv6] into [b] starting
+      from offset [off] within [b].  [b] must be at least [off+16] bytes long or
+      an error is returned. *)
+  val write_octets : ?off:int -> t -> bytes -> (unit, [> `Msg of string ]) result
+ 
+  (** [to_octets ipv6] returns the 16 bytes representing the [ipv6] octets. *)
+  val to_octets : t -> string
 
   (** {3 Int conversion} *)
 
@@ -436,7 +449,7 @@ module V6 : sig
     val network_address : t -> addr -> addr
 
     (** [of_string_exn cidr] is the subnet prefix represented by the CIDR
-        string, [cidr]. Raises [Parse_error] if [cidr] is not a valid
+        string, [cidr]. Raises {!Parse_error} if [cidr] is not a valid
         representation of a CIDR notation routing prefix. *)
     val of_string_exn : string -> t
 
@@ -457,7 +470,7 @@ module V6 : sig
     val pp : Format.formatter -> t -> unit [@@ocaml.toplevel_printer]
 
     (** [of_address_string_exn cidr_addr] is the address and prefix
-        represented by [cidr_addr]. Raises [Parse_error] if [cidr_addr] is not
+        represented by [cidr_addr]. Raises {!Parse_error} if [cidr_addr] is not
         a valid representation of a CIDR-scoped address. *)
     val of_address_string_exn : string -> t * addr
 
@@ -642,7 +655,7 @@ module Prefix : sig
   val pp : Format.formatter -> t -> unit [@@ocaml.toplevel_printer]
 
   (** [of_string_exn cidr] is the subnet prefix represented by the CIDR
-      string, [cidr]. Raises [Parse_error] if [cidr] is not a valid
+      string, [cidr]. Raises {!Parse_error} if [cidr] is not a valid
       representation of a CIDR notation routing prefix. *)
   val of_string_exn : string -> t
 
diff --git a/lib/macaddr.ml b/lib/macaddr.ml
index d656af8..3c66a79 100644
--- a/lib/macaddr.ml
+++ b/lib/macaddr.ml
@@ -28,12 +28,12 @@ type t = Bytes.t (* length 6 only *)
 let compare = Bytes.compare
 
 (* Raw MAC address off the wire (network endian) *)
-let of_bytes_exn x =
+let of_octets_exn x =
   if String.length x <> 6
   then raise (Parse_error ("MAC is exactly 6 bytes", x))
   else Bytes.of_string x
 
-let of_bytes x = try_with_result of_bytes_exn x
+let of_octets x = try_with_result of_octets_exn x
 
 let int_of_hex_char c =
   let c = int_of_char (Char.uppercase_ascii c) - 48 in
@@ -109,7 +109,7 @@ let to_string ?(sep=':') x =
     (chri x 4) sep
     (chri x 5)
 
-let to_bytes x = Bytes.to_string x
+let to_octets x = Bytes.to_string x
 
 let pp ppf i =
   Format.fprintf ppf "%s" (to_string i)
diff --git a/lib/macaddr.mli b/lib/macaddr.mli
index a951086..1db34fb 100644
--- a/lib/macaddr.mli
+++ b/lib/macaddr.mli
@@ -26,27 +26,28 @@ exception Parse_error of string * string
 (** Type of the hardware address (MAC) of an ethernet interface. *)
 type t
 
-(** {2 Functions converting MAC addresses to/from bytes/string} *)
+(** {2 Functions converting MAC addresses to/from octets/string} *)
 
-(** [of_bytes_exn buf] is the hardware address extracted from
+(** [of_octets_exn buf] is the hardware address extracted from
     [buf]. Raises [Parse_error] if [buf] has not length 6. *)
-val of_bytes_exn : string -> t
+val of_octets_exn : string -> t
 
-(** Same as above but returns an option type instead of raising an
-    exception. *)
-val of_bytes : string -> (t, [> `Msg of string]) result
+(** Same as {!of_octets_exn} but returns a result type instead of
+    raising an exception. *)
+val of_octets : string -> (t, [> `Msg of string]) result
 
-(** [of_string_exn mac_string] is the hardware address represented by
-    [mac_string]. Raises [Parse_error] if [mac_string] is not a
+(** [of_string_exn mac_string] is the human-readable hardware address represented by
+    [mac_string]. Raises {!Parse_error} if [mac_string] is not a
     valid representation of a MAC address. *)
 val of_string_exn : string -> t
 
-(** Same as above but returns an option type instead of raising an
+(** Same as {!of_string_exn} but returns a result type instead of raising an
     exception. *)
 val of_string : string ->  (t, [> `Msg of string]) result
 
-(** [to_bytes mac_addr] is a string of size 6 encoding [mac_addr]. *)
-val to_bytes : t -> string
+(** [to_octets mac_addr] is a string of size 6 encoding [mac_addr] as a
+    sequence of bytes. *)
+val to_octets : t -> string
 
 (** [to_string ?(sep=':') mac_addr] is the [sep]-separated string representation
     of [mac_addr], i.e. [xx:xx:xx:xx:xx:xx]. *)
diff --git a/lib_test/test_ipaddr.ml b/lib_test/test_ipaddr.ml
index c5ad005..ddc46c1 100644
--- a/lib_test/test_ipaddr.ml
+++ b/lib_test/test_ipaddr.ml
@@ -20,7 +20,6 @@ open Ipaddr
 
 let error s msg = s, Parse_error (msg,s)
 let need_more s = error s "not enough data"
-let too_much s  = error s "too much data"
 let bad_char i s =
   error s (Printf.sprintf "invalid character '%c' at %d" s.[i] i)
 
@@ -89,16 +88,15 @@ module Test_v4 = struct
   let test_bytes_rt () =
     let addr = "\254\099\003\128" in
     assert_equal ~msg:(String.escaped addr)
-      V4.(to_bytes (of_bytes_exn addr)) addr
+      V4.(to_octets (of_octets_exn addr)) addr
 
   let test_bytes_rt_bad () =
     let addrs = [
       need_more "\254\099\003";
-      too_much "\254\099\003\128\001";
     ] in
     List.iter (fun (addr,exn) ->
       assert_raises ~msg:(String.escaped addr) exn
-        (fun () -> V4.of_bytes_exn addr)
+        (fun () -> V4.of_octets_exn addr)
     ) addrs
 
   let test_int32_rt () =
@@ -273,7 +271,7 @@ module Test_v4 = struct
     assert_equal ~msg:"localhost" true V4.(Prefix.(mem localhost loopback))
 
   let test_multicast_mac () =
-    let ip = V4.of_bytes_exn "\xff\xbf\x9f\x8f" in
+    let ip = V4.of_octets_exn "\xff\xbf\x9f\x8f" in
     let multicast = V4.Prefix.(network_address multicast ip) in
     let unicast_mac_str   = Macaddr.to_string (V4.multicast_to_mac ip) in
     let multicast_mac_str = Macaddr.to_string (V4.multicast_to_mac multicast) in
@@ -405,18 +403,16 @@ module Test_v6 = struct
     let addr =
       "\000\000\000\000\000\000\000\000\000\000\255\255\192\168\000\001"
     in
-    let v6 = V6.of_bytes_exn addr in
-    assert_equal ~msg:(String.escaped addr) V6.(to_bytes v6) addr
+    let v6 = V6.of_octets_exn addr in
+    assert_equal ~msg:(String.escaped addr) V6.(to_octets v6) addr
 
   let test_bytes_rt_bad () =
     let addrs = [
       need_more "\000\000\000\000\000\000\000\000\000\000\255\255\192\168\001";
-      too_much
-        "\000\000\000\000\000\000\000\000\000\000\255\255\192\168\000\000\001";
     ] in
     List.iter (fun (addr,exn) ->
       assert_raises ~msg:(String.escaped addr) exn
-        (fun () -> V6.of_bytes_exn addr)
+        (fun () -> V6.of_octets_exn addr)
     ) addrs
 
   let test_int32_rt () =
diff --git a/lib_test/test_macaddr.ml b/lib_test/test_macaddr.ml
index 678fc3c..d9c8822 100644
--- a/lib_test/test_macaddr.ml
+++ b/lib_test/test_macaddr.ml
@@ -50,7 +50,7 @@ let test_string_rt_bad () =
 
 let test_bytes_rt () =
   let addr = "\254\099\003\128\000\000" in
-  assert_equal ~msg:(String.escaped addr) (to_bytes (of_bytes_exn addr)) addr
+  assert_equal ~msg:(String.escaped addr) (to_octets (of_octets_exn addr)) addr
 
 let test_bytes_rt_bad () =
   let addrs = [
@@ -58,7 +58,7 @@ let test_bytes_rt_bad () =
     "\254\099\003\128\000\000\233";
   ] in
   List.iter (fun addr ->
-    assert_result_failure ~msg:(String.escaped addr) (of_bytes addr)) addrs
+    assert_result_failure ~msg:(String.escaped addr) (of_octets addr)) addrs
 
 let test_make_local () =
   let () = Random.self_init () in
@@ -66,10 +66,10 @@ let test_make_local () =
   let local_addr = make_local bytegen in
   assert_equal ~msg:"is_local" (is_local local_addr) true;
   assert_equal ~msg:"is_unicast" (is_unicast local_addr) true;
-  assert_equal ~msg:"localize" (to_bytes local_addr).[0] (Char.chr 254);
+  assert_equal ~msg:"localize" (to_octets local_addr).[0] (Char.chr 254);
   for i=1 to 5 do
     assert_equal ~msg:("addr.["^(string_of_int i)^"]")
-      (to_bytes local_addr).[i] (Char.chr (bytegen i))
+      (to_octets local_addr).[i] (Char.chr (bytegen i))
   done;
   assert_equal ~msg:"get_oui" (get_oui local_addr)
     ((254 lsl 16) + (254 lsl 8) + 253)