diff --git a/runtime/io.js b/runtime/io.js
index dba2c2f47d..467a46a751 100644
--- a/runtime/io.js
+++ b/runtime/io.js
@@ -170,14 +170,14 @@ function caml_ml_close_channel (chanid) {
 }
 
 //Provides: caml_ml_channel_size
-//Requires: caml_ml_string_length, caml_ml_channels
+//Requires: caml_ml_channels
 function caml_ml_channel_size(chanid) {
   var chan = caml_ml_channels[chanid];
   return chan.file.length();
 }
 
 //Provides: caml_ml_channel_size_64
-//Requires: caml_ml_channel_size,caml_int64_of_float,caml_ml_string_length, caml_ml_channels
+//Requires: caml_int64_of_float,caml_ml_channels
 function caml_ml_channel_size_64(chanid) {
   var chan = caml_ml_channels[chanid];
   return caml_int64_of_float(chan.file.length ());
@@ -199,17 +199,17 @@ function caml_ml_set_channel_refill(chanid,f) {
 }
 
 //Provides: caml_ml_refill_input
-//Requires: caml_ml_string_length
+//Requires: caml_ml_bytes_length
 function caml_ml_refill_input (chan) {
   var str = chan.refill();
-  var str_len = caml_ml_string_length(str);
+  var str_len = caml_ml_bytes_length(str);
   if (str_len == 0) chan.refill = null;
   chan.file.write(chan.file.length(), str, 0, str_len);
   return str_len;
 }
 
 //Provides: caml_ml_may_refill_input
-//Requires: caml_ml_string_length, caml_ml_refill_input, caml_ml_channels
+//Requires: caml_ml_refill_input, caml_ml_channels
 function caml_ml_may_refill_input (chanid) {
   var chan = caml_ml_channels[chanid];
   if (chan.refill == null) return;
@@ -251,7 +251,7 @@ function caml_input_value (chanid) {
 
 //Provides: caml_ml_input_char
 //Requires: caml_raise_end_of_file, caml_array_bound_error
-//Requires: caml_ml_string_length, caml_ml_may_refill_input, caml_ml_channels
+//Requires: caml_ml_may_refill_input, caml_ml_channels
 function caml_ml_input_char (chanid) {
   var chan = caml_ml_channels[chanid];
   caml_ml_may_refill_input(chanid);
@@ -264,7 +264,7 @@ function caml_ml_input_char (chanid) {
 
 //Provides: caml_ml_input_int
 //Requires: caml_raise_end_of_file
-//Requires: caml_ml_string_length, caml_string_unsafe_get, caml_ml_refill_input, caml_ml_channels
+//Requires: caml_ml_refill_input, caml_ml_channels
 function caml_ml_input_int (chanid) {
   var chan = caml_ml_channels[chanid];
   var file = chan.file;
@@ -308,7 +308,7 @@ function caml_ml_pos_in(chanid) {return caml_ml_channels[chanid].offset}
 function caml_ml_pos_in_64(chanid) {return caml_int64_of_float(caml_ml_channels[chanid].offset)}
 
 //Provides: caml_ml_input_scan_line
-//Requires: caml_array_bound_error, caml_ml_string_length
+//Requires: caml_array_bound_error
 //Requires: caml_ml_may_refill_input, caml_ml_channels
 function caml_ml_input_scan_line(chanid){
   var chan = caml_ml_channels[chanid];
@@ -344,14 +344,14 @@ function caml_ml_flush (chanid) {
 
 //output to out_channel
 
-//Provides: caml_ml_output
-//Requires: caml_ml_flush,caml_ml_string_length
+//Provides: caml_ml_output_bytes
+//Requires: caml_ml_flush,caml_ml_bytes_length
 //Requires: caml_create_bytes, caml_blit_bytes, caml_raise_sys_error, caml_ml_channels
-function caml_ml_output (chanid,buffer,offset,len) {
+function caml_ml_output_bytes(chanid,buffer,offset,len) {
     var chan = caml_ml_channels[chanid];
     if(! chan.opened) caml_raise_sys_error("Cannot output to a closed channel");
     var string;
-    if(offset == 0 && caml_ml_string_length(buffer) == len)
+    if(offset == 0 && caml_ml_bytes_length(buffer) == len)
         string = buffer;
     else {
         string = caml_create_bytes(len);
@@ -369,13 +369,15 @@ function caml_ml_output (chanid,buffer,offset,len) {
     return 0;
 }
 
-//Provides: caml_ml_output_bytes
-//Requires: caml_ml_output
-var caml_ml_output_bytes = caml_ml_output
+//Provides: caml_ml_output
+//Requires: caml_ml_output_bytes
+function caml_ml_output(chanid,buffer,offset,len){
+    return caml_ml_output_bytes(chanid,buffer,offset,len);
+}
 
 //Provides: caml_ml_output_char
 //Requires: caml_ml_output
-//Requires: caml_new_string, caml_ml_channels
+//Requires: caml_new_string
 function caml_ml_output_char (chanid,c) {
     var s = caml_new_string(String.fromCharCode(c));
     caml_ml_output(chanid,s,0,1);
@@ -383,7 +385,7 @@ function caml_ml_output_char (chanid,c) {
 }
 
 //Provides: caml_output_value
-//Requires: caml_output_value_to_string, caml_ml_output,caml_ml_string_length, caml_ml_channels
+//Requires: caml_output_value_to_string, caml_ml_output,caml_ml_string_length
 function caml_output_value (chanid,v,_flags) {
   var s = caml_output_value_to_string(v);
   caml_ml_output(chanid,s,0,caml_ml_string_length(s));
diff --git a/runtime/marshal.js b/runtime/marshal.js
index 8baf1b6880..e351844d07 100644
--- a/runtime/marshal.js
+++ b/runtime/marshal.js
@@ -317,13 +317,13 @@ function caml_input_value_from_reader(reader, ofs) {
 }
 
 //Provides: caml_marshal_data_size mutable
-//Requires: caml_failwith, caml_string_unsafe_get
+//Requires: caml_failwith, caml_bytes_unsafe_get
 function caml_marshal_data_size (s, ofs) {
   function get32(s,i) {
-    return (caml_string_unsafe_get(s, i) << 24) |
-           (caml_string_unsafe_get(s, i + 1) << 16) |
-           (caml_string_unsafe_get(s, i + 2) << 8) |
-            caml_string_unsafe_get(s, i + 3);
+    return (caml_bytes_unsafe_get(s, i) << 24) |
+           (caml_bytes_unsafe_get(s, i + 1) << 16) |
+           (caml_bytes_unsafe_get(s, i + 2) << 8) |
+            caml_bytes_unsafe_get(s, i + 3);
   }
   if (get32(s, ofs) != (0x8495A6BE|0))
     caml_failwith("Marshal.data_size: bad object");
diff --git a/runtime/md5.js b/runtime/md5.js
index db0b5ecf59..70efc750d7 100644
--- a/runtime/md5.js
+++ b/runtime/md5.js
@@ -19,7 +19,7 @@
 
 
 //Provides: caml_md5_chan
-//Requires: caml_md5_string, caml_string_of_array,caml_ml_string_length, caml_ml_channels
+//Requires: caml_md5_string, caml_string_of_array,caml_ml_channels
 //Requires: caml_raise_end_of_file, caml_create_bytes  
 function caml_md5_chan(chanid,len){
   var chan = caml_ml_channels[chanid];
diff --git a/runtime/mlString.js b/runtime/mlString.js
index 16ad0fa502..cbab27e3d2 100644
--- a/runtime/mlString.js
+++ b/runtime/mlString.js
@@ -213,20 +213,9 @@ function caml_bytes_unsafe_get (s, i) {
 }
 
 //Provides: caml_string_unsafe_set
-//Requires: caml_convert_string_to_array
-function caml_string_unsafe_set (s, i, c) {
-  // The OCaml compiler uses Char.unsafe_chr on integers larger than 255!
-  c &= 0xff;
-  if (s.t != 4 /* ARRAY */) {
-    if (i == s.c.length) {
-      s.c += String.fromCharCode (c);
-      if (i + 1 == s.l) s.t = 0; /*BYTES | UNKOWN*/
-      return 0;
-    }
-    caml_convert_string_to_array (s);
-  }
-  s.c[i] = c;
-  return 0;
+//Requires: caml_bytes_unsafe_set
+function caml_string_unsafe_set(s, i, c) {
+    return caml_bytes_unsafe_set(s, i, c)
 }
 
 //Provides: caml_bytes_unsafe_set
@@ -299,7 +288,7 @@ function caml_bytes_get (s, i) {
 }
 
 //Provides: caml_string_set
-//Requires: caml_string_bound_error, caml_string_unsafe_set
+//Requires: caml_string_unsafe_set
 function caml_string_set (s, i, c) {
   if (i >>> 0 >= s.l) caml_string_bound_error();
   return caml_string_unsafe_set (s, i, c);