diff --git a/_oasis b/_oasis
index 73a75682..1bf48bc4 100644
--- a/_oasis
+++ b/_oasis
@@ -49,6 +49,7 @@ Library "containers"
                     CCKList, CCInt, CCBool, CCArray, CCOrd, CCIO,
                     CCRandom, CCKTree, CCTrie, CCString, CCHashtbl,
                     CCFlatHashtbl, CCSexp, CCMap
+  BuildDepends:     bytes
   XMETARequires:    cppo
   FindlibName:      containers
 
diff --git a/core/CCSequence.mli b/core/CCSequence.mli
index e036693b..7e3b6a63 100644
--- a/core/CCSequence.mli
+++ b/core/CCSequence.mli
@@ -604,7 +604,15 @@ module IO : sig
       @param mode default [0o644]
       @param flags used by [open_out_gen]. Default: [[Open_creat;Open_wronly]]. *)
 
+  val write_bytes_to : ?mode:int -> ?flags:open_flag list ->
+                       string -> Bytes.t t -> unit
+  (** @since NEXT_RELEASE *)
+
   val write_lines : ?mode:int -> ?flags:open_flag list ->
                     string -> string t -> unit
   (** Same as {!write_to}, but intercales ['\n'] between each string *)
+
+  val write_bytes_lines : ?mode:int -> ?flags:open_flag list ->
+                    string -> Bytes.t t -> unit
+  (** @since NEXT_RELEASE *)
 end