diff --git a/aurochs/compiler.ml b/aurochs/compiler.ml
index 3ef8f08..b35b606 100644
--- a/aurochs/compiler.ml
+++ b/aurochs/compiler.ml
@@ -16,6 +16,6 @@ let compile ?(start="start") ?(base="") ?(root="root") ?(check=true) u =
     end;
   let peg_canonified = Canonify.canonify_grammar ~start peg in
   let pg = Noggie.generate_code ~start ~root peg_canonified in
-  Bytes.with_buffer_sink (Noggie.put_program pg peg)
+  Bytes_.with_buffer_sink (Noggie.put_program pg peg)
 
 let _ = compiler := compile
diff --git a/aurochs/process.ml b/aurochs/process.ml
index 732dec6..2f94728 100644
--- a/aurochs/process.ml
+++ b/aurochs/process.ml
@@ -418,7 +418,7 @@ let process fno =
         info `Normal "Loading NOG bytecode from file %s" fn;
         Aurochs.load (`File fn)
     | None ->
-        Bytes.with_buffer_sink (Noggie.put_program (!< pg) (!< peg))
+        Bytes_.with_buffer_sink (Noggie.put_program (!< pg) (!< peg))
     )
   in
 
diff --git a/backends/camelus.ml b/backends/camelus.ml
index f6a99a7..11388f1 100644
--- a/backends/camelus.ml
+++ b/backends/camelus.ml
@@ -210,7 +210,7 @@ let generate_implementation ?(pack=true) fn start peg (pg : (string, string) pro
       build_printer "node_name" !Opt.node_prefix node_numbers;
       build_printer "attribute_name" !Opt.attribute_prefix attribute_numbers;
 
-      let u = Bytes.with_buffer_sink (Noggie.put_program pg peg) in
+      let u = Bytes_.with_buffer_sink (Noggie.put_program pg peg) in
       fp oc "\n";
       fp oc "let binary =\n";
       Stringifier.print_ocaml_string ~indent:4 () oc u;
diff --git a/backends/noggie.ml b/backends/noggie.ml
index 0bd301a..53a93a3 100644
--- a/backends/noggie.ml
+++ b/backends/noggie.ml
@@ -489,14 +489,14 @@ let put_program pg peg sk =
 
 let put_program pg peg sk =
   let sum64 = ref 0L in
-  let sk_sum64 = Bytes.checksum64 sum64 sk in
+  let sk_sum64 = Bytes_.checksum64 sum64 sk in
   put_program pg peg sk_sum64;
   Pack.write_uint64 sk !sum64
 (* ***)
 (*** save_program *)
 let save_program_ascii ~prologue ~epilogue fn pg peg =
   Util.with_file_output fn (fun oc ->
-    let u = Bytes.with_buffer_sink (put_program pg peg) in
+    let u = Bytes_.with_buffer_sink (put_program pg peg) in
     let m = String.length u in
     output_string oc prologue;
     for i = 0 to m - 1 do
@@ -508,7 +508,7 @@ let save_program_ascii ~prologue ~epilogue fn pg peg =
     output_string oc epilogue)
 (* ***)
 (*** save_program *)
-let save_program fn pg peg = Util.with_binary_file_output fn (fun oc -> put_program pg peg (Bytes.sink_of_out_channel oc))
+let save_program fn pg peg = Util.with_binary_file_output fn (fun oc -> put_program pg peg (Bytes_.sink_of_out_channel oc))
 (* ***)
 (*** generate *)
 let generate fn ?(start="start") peg =
diff --git a/pack/pack.ml b/pack/pack.ml
index 2f1c167..bff7eb1 100644
--- a/pack/pack.ml
+++ b/pack/pack.ml
@@ -1,11 +1,11 @@
 (* Pack *)
 
-open Bytes;;
+open Bytes_;;
 open Int_operators;;
 
-type packer = Bytes.sink;;
+type packer = Bytes_.sink;;
 (*** write_byte *)
-let write_byte sk x = Bytes.put_byte sk x;;
+let write_byte sk x = Bytes_.put_byte sk x;;
 (* ***)
 (*** write_int64 *)
 let write_int64 sk x =
@@ -77,7 +77,7 @@ let write_int sk x = write_int64 sk (!!!! x);;
 (*** test *)
 let test fn =
   let oc = open_out_bin fn in
-  let sk = Bytes.sink_of_out_channel oc in
+  let sk = Bytes_.sink_of_out_channel oc in
   let rec loop i x =
     let y = x in
     Printf.printf ">>> 0x%08Lx %Ld\n%!" y y;
diff --git a/pack/pack.mli b/pack/pack.mli
index 3e8438f..0fd8059 100644
--- a/pack/pack.mli
+++ b/pack/pack.mli
@@ -1,6 +1,6 @@
 (* Pack *)
 
-type packer = Bytes.sink;;
+type packer = Bytes_.sink;;
 
 val write_byte : packer -> int -> unit
 val write_int64 : packer -> int64 -> unit
diff --git a/util/bytes.ml b/util/bytes_.ml
similarity index 99%
rename from util/bytes.ml
rename to util/bytes_.ml
index 64f7048..306b193 100644
--- a/util/bytes.ml
+++ b/util/bytes_.ml
@@ -1,4 +1,4 @@
-(* Bytes *)
+(* Bytes_ *)
 
 open Int_operators;;
 
diff --git a/util/bytes.mli b/util/bytes_.mli
similarity index 99%
rename from util/bytes.mli
rename to util/bytes_.mli
index fa82fd0..3a49bd0 100644
--- a/util/bytes.mli
+++ b/util/bytes_.mli
@@ -1,4 +1,4 @@
-(* Bytes *)
+(* Bytes_ *)
 
 (** Module for byte sinks and sources. *)