diff --git a/configure b/configure
index 207c4df..4cdd5e5 100755
--- a/configure
+++ b/configure
@@ -632,6 +632,7 @@ CURLLIBS
 ac_prefix_program
 OCAML_PKG_lwt_ppx
 OCAML_PKG_lwt_unix
+OCAML_PKG_bytes
 OCAMLFIND
 OCAMLBUILD
 OCAMLDOC
@@ -4091,6 +4092,30 @@ fi
 
 
 
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for OCaml findlib package bytes" >&5
+$as_echo_n "checking for OCaml findlib package bytes... " >&6; }
+
+  unset found
+  unset pkg
+  found=no
+  for pkg in bytes  ; do
+    if $OCAMLFIND query $pkg >/dev/null 2>/dev/null; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: result: found" >&5
+$as_echo "found" >&6; }
+      OCAML_PKG_bytes=$pkg
+      found=yes
+      break
+    fi
+  done
+  if test "$found" = "no" ; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
+$as_echo "not found" >&6; }
+    OCAML_PKG_bytes=no
+  fi
+
+
+
+
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for OCaml findlib package lwt.unix" >&5
 $as_echo_n "checking for OCaml findlib package lwt.unix... " >&6; }
 
@@ -4241,6 +4266,7 @@ fi
 
 
 
+
 if test "$OCAMLFIND" == "no"; then :
   $OCAMLC -I +compiler-libs ocamlcommon.cma print_ext.ml -o print_ext
 else
diff --git a/configure.ac b/configure.ac
index 363969d..750b283 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,6 +28,7 @@ AC_PROG_INSTALL()
 AC_PROG_OCAML()
 AC_PROG_FINDLIB()
 
+AC_CHECK_OCAML_PKG([bytes])
 AC_CHECK_OCAML_PKG([lwt.unix])
 AC_CHECK_OCAML_PKG([lwt.ppx])
 
@@ -39,6 +40,7 @@ AC_SUBST(CURLLIBS)
 AC_SUBST(OCAMLLIB)
 AC_SUBST(INSTALLDIR)
 AC_SUBST(OCAMLFIND)
+AC_SUBST(OCAML_PKG_bytes)
 AC_SUBST(OCAML_PKG_lwt_unix)
 AC_SUBST(OCAML_PKG_lwt_ppx)
 
diff --git a/examples/Makefile.in b/examples/Makefile.in
index 560e285..86a5a6b 100644
--- a/examples/Makefile.in
+++ b/examples/Makefile.in
@@ -16,7 +16,10 @@ LFLAGS		= -g -I .. -ccopt -L..
 OCURLLIB	= curl.cma unix.cma threads.cma
 OCURLOPTLIB	= curl.cmxa unix.cmxa threads.cmxa
 
-TARGETS = ocurl oput ominimal ossl ocurl_test_threads opar test_cb_exn test_memory_leaks
+TARGETS = ocurl ominimal ossl ocurl_test_threads opar test_cb_exn test_memory_leaks
+ifneq (@OCAML_PKG_bytes@,no)
+TARGETS += oput
+endif
 ifneq (@OCAML_PKG_lwt_unix@,no)
 TARGETS += test_lwt_unit
 ifneq (@OCAML_PKG_lwt_ppx@,no)
@@ -25,7 +28,10 @@ endif
 endif
 
 ifeq (@OCAMLBEST@,opt)
-TARGETS	+= ocurl.opt oput.opt ominimal.opt ossl.opt ocurl_test_threads.opt opar.opt test_cb_exn.opt test_memory_leaks.opt
+TARGETS	+= ocurl.opt ominimal.opt ossl.opt ocurl_test_threads.opt opar.opt test_cb_exn.opt test_memory_leaks.opt
+ifneq (@OCAML_PKG_bytes@,no)
+TARGETS += oput.opt
+endif
 ifneq (@OCAML_PKG_lwt_unix@,no)
 TARGETS += test_lwt_unit.opt
 ifneq (@OCAML_PKG_lwt_ppx@,no)
@@ -50,6 +56,12 @@ test_lwt_unit: ../curl.cma ../curl_lwt.cmo test_lwt_unit.ml
 test_lwt_unit.opt: ../curl.cmxa ../curl_lwt.cmx test_lwt_unit.ml
 	$(FINDLIB) opt $(FINDLIB_LWT_FLAGS) $(LFLAGS) $^ -o $@
 
+oput: ../curl.cma oput.ml
+	$(FINDLIB) c -custom -package bytes -linkpkg $(LFLAGS) $^ -o $@
+
+oput.opt: ../curl.cmxa oput.ml
+	$(FINDLIB) opt -package bytes -linkpkg $(LFLAGS) $^ -o $@
+
 %: %.cmo ../curl.cma
 		$(OCBYTE) -custom $(LFLAGS) $(OCURLLIB) $< -o $@
 
diff --git a/examples/oput.ml b/examples/oput.ml
index 25b043b..c1da561 100644
--- a/examples/oput.ml
+++ b/examples/oput.ml
@@ -7,14 +7,15 @@
 let counter = ref 0
 
 let reader file maxBytes =
-  let buffer = String.make maxBytes ' ' in
+  let buffer = Bytes.create maxBytes in
   let readBytes = input file buffer 0 maxBytes in
-    if readBytes = 0 then ""
-    else
-      begin
-	counter := !counter + readBytes;
-	String.sub buffer 0 readBytes
-      end
+  if readBytes = 0 then
+    ""
+  else
+  begin
+    counter := !counter + readBytes;
+	  Bytes.sub_string buffer 0 readBytes
+  end
 
 let _ =
   if Array.length Sys.argv = 3 then