diff --git a/js/module.ml b/js/module.ml
index 6e3e13ab..c60158c2 100644
--- a/js/module.ml
+++ b/js/module.ml
@@ -2,6 +2,28 @@ open Js_of_ocaml
 open Js_of_ocaml.Js
 open Js_of_ocaml.Js.Unsafe
 
+let make_encoder () = new_obj global ##. TextEncoder [||]
+
+let encode encoder (value : string) =
+  meth_call encoder "encode" [| inject (string value) |]
+
+let make_decoder () = new_obj global ##. TextDecoder [||]
+
+let decode decoder u8a = to_string (meth_call decoder "decode" [| inject u8a |])
+
+(* Uint8Array/Byte utilities *)
+let u8a_to_bytes u8a =
+  let decoder = make_decoder () in
+  Bytes.of_string (decode decoder u8a)
+
+let bytes_to_u8a byts =
+  let encoder = make_encoder () in
+  encode encoder (Bytes.to_string byts)
+
+let string_to_u8a str =
+  let encoder = make_encoder () in
+  encode encoder str
+
 type t
 
 let create () = new_obj global ##. binaryen ##. Module [||]
@@ -10,9 +32,7 @@ let dispose wasm_mod = ignore (meth_call wasm_mod "dispose" [||])
 
 (* TODO: Check the unit8Array conversion *)
 let add_custom_section wasm_mod name contents =
-  let contents =
-    meth_call Typed_array.uint8Array "from" [| inject (string contents) |]
-  in
+  let contents = string_to_u8a contents in
   ignore
     (meth_call wasm_mod "addCustomSection"
        [| inject (string name); inject contents |])
@@ -88,13 +108,6 @@ let run_passes wasm_mod passes =
 
 let auto_drop wasm_mod = meth_call wasm_mod "autoDrop" [||]
 
-let uint8array_to_bytes u8a =
-  Bytes.of_string (Typed_array.String.of_uint8Array u8a)
-
-let bytes_to_uint8array byts =
-  meth_call Typed_array.uint8Array "from"
-    [| inject (string (Bytes.to_string byts)) |]
-
 (* TODO: This returns the wrong type, need to convert from `Uint8Array` to `bytes` *)
 let write wasm_mod sourcemap_url =
   match sourcemap_url with
@@ -102,10 +115,10 @@ let write wasm_mod sourcemap_url =
       let obj = meth_call wasm_mod "emitBinary" [| inject url |] in
       let binary = get obj "binary" in
       let soucemap = get obj "soureMap" in
-      (uint8array_to_bytes binary, Some soucemap)
+      (u8a_to_bytes binary, Some soucemap)
   | None ->
       let binary = meth_call wasm_mod "emitBinary" [||] in
-      (uint8array_to_bytes binary, None)
+      (u8a_to_bytes binary, None)
 
 let write_text wasm_mod =
   let text = meth_call wasm_mod "emitText" [||] in
@@ -113,7 +126,7 @@ let write_text wasm_mod =
 
 (* TODO: This doesn't handle `bytes` correctly *)
 let read byts =
-  let data = bytes_to_uint8array byts in
+  let data = bytes_to_u8a byts in
   meth_call global##.binaryen "readBinary" [| inject data |]
 
 let interpret wasm_mod = meth_call wasm_mod "interpret" [||]
diff --git a/test/test.expected b/test/test.expected
index 92737a9b..0fafc738 100644
--- a/test/test.expected
+++ b/test/test.expected
@@ -7,3 +7,12 @@
   )
  )
 )
+(module
+ (type $i32_i32_=>_i32 (func (param i32 i32) (result i32)))
+ (func $0 (param $0 i32) (param $1 i32) (result i32)
+  (i32.add
+   (local.get $0)
+   (local.get $1)
+  )
+ )
+)
diff --git a/test/test.ml b/test/test.ml
index ef87b77e..48ea9ba3 100644
--- a/test/test.ml
+++ b/test/test.ml
@@ -19,4 +19,14 @@ let adder = Function.add_function wasm_mod "adder" params results [||] add
 
 let _ = Module.print wasm_mod
 
+let byts, _ = Module.write wasm_mod None
+
+let new_mod = Module.read byts
+
+let _ = Module.validate new_mod
+
+let _ = Module.print new_mod
+
 let _ = Module.dispose wasm_mod
+
+let _ = Module.dispose new_mod