diff --git a/bytecomp/bytelibrarian.ml b/bytecomp/bytelibrarian.ml
index a905801fe..c380dbc5e 100644
--- a/bytecomp/bytelibrarian.ml
+++ b/bytecomp/bytelibrarian.ml
@@ -55,7 +55,7 @@ let add_ccobjs l =
     lib_dllibs := !lib_dllibs @ l.lib_dllibs
   end
 
-let copy_object_file ppf oc name =
+let copy_object_file oc name =
   let file_name =
     try
       find_in_path !load_path name
@@ -68,7 +68,7 @@ let copy_object_file ppf oc name =
       let compunit_pos = input_binary_int ic in
       seek_in ic compunit_pos;
       let compunit = (input_value ic : compilation_unit) in
-      Bytelink.check_consistency ppf file_name compunit;
+      Bytelink.check_consistency file_name compunit;
       copy_compunit ic oc compunit;
       close_in ic;
       [compunit]
@@ -77,7 +77,7 @@ let copy_object_file ppf oc name =
       let toc_pos = input_binary_int ic in
       seek_in ic toc_pos;
       let toc = (input_value ic : library) in
-      List.iter (Bytelink.check_consistency ppf file_name) toc.lib_units;
+      List.iter (Bytelink.check_consistency file_name) toc.lib_units;
       add_ccobjs toc;
       List.iter (copy_compunit ic oc) toc.lib_units;
       close_in ic;
@@ -88,14 +88,14 @@ let copy_object_file ppf oc name =
     End_of_file -> close_in ic; raise(Error(Not_an_object_file file_name))
   | x -> close_in ic; raise x
 
-let create_archive ppf file_list lib_name =
+let create_archive file_list lib_name =
   let outchan = open_out_bin lib_name in
   try
     output_string outchan cma_magic_number;
     let ofs_pos_toc = pos_out outchan in
     output_binary_int outchan 0;
     let units =
-      List.flatten(List.map (copy_object_file ppf outchan) file_list) in
+      List.flatten(List.map (copy_object_file outchan) file_list) in
     let toc =
       { lib_units = units;
         lib_custom = !Clflags.custom_runtime;
diff --git a/bytecomp/bytelibrarian.mli b/bytecomp/bytelibrarian.mli
index 04a0316a8..3670730d6 100644
--- a/bytecomp/bytelibrarian.mli
+++ b/bytecomp/bytelibrarian.mli
@@ -22,7 +22,7 @@
       content table = list of compilation units
 *)
 
-val create_archive: Format.formatter -> string list -> string -> unit
+val create_archive: string list -> string -> unit
 
 type error =
     File_not_found of string
diff --git a/bytecomp/bytelink.ml b/bytecomp/bytelink.ml
index 5745b9f1d..1337cfcd1 100644
--- a/bytecomp/bytelink.ml
+++ b/bytecomp/bytelink.ml
@@ -169,7 +169,7 @@ let crc_interfaces = Consistbl.create ()
 let interfaces = ref ([] : string list)
 let implementations_defined = ref ([] : (string * string) list)
 
-let check_consistency ppf file_name cu =
+let check_consistency file_name cu =
   begin try
     List.iter
       (fun (name, crco) ->
@@ -186,7 +186,7 @@ let check_consistency ppf file_name cu =
   end;
   begin try
     let source = List.assoc cu.cu_name !implementations_defined in
-    Location.print_warning (Location.in_file file_name) ppf
+    Location.prerr_warning (Location.in_file file_name)
       (Warnings.Multiple_definition(cu.cu_name,
                                     Location.show_filename file_name,
                                     Location.show_filename source))
@@ -208,8 +208,8 @@ let debug_info = ref ([] : (int * Instruct.debug_event list * string list) list)
 
 (* Link in a compilation unit *)
 
-let link_compunit ppf output_fun currpos_fun inchan file_name compunit =
-  check_consistency ppf file_name compunit;
+let link_compunit output_fun currpos_fun inchan file_name compunit =
+  check_consistency file_name compunit;
   seek_in inchan compunit.cu_pos;
   let code_block = LongString.input_bytes inchan compunit.cu_codesize in
   Symtable.patch_object code_block compunit.cu_reloc;
@@ -230,10 +230,10 @@ let link_compunit ppf output_fun currpos_fun inchan file_name compunit =
 
 (* Link in a .cmo file *)
 
-let link_object ppf output_fun currpos_fun file_name compunit =
+let link_object output_fun currpos_fun file_name compunit =
   let inchan = open_in_bin file_name in
   try
-    link_compunit ppf output_fun currpos_fun inchan file_name compunit;
+    link_compunit output_fun currpos_fun inchan file_name compunit;
     close_in inchan
   with
     Symtable.Error msg ->
@@ -243,14 +243,14 @@ let link_object ppf output_fun currpos_fun file_name compunit =
 
 (* Link in a .cma file *)
 
-let link_archive ppf output_fun currpos_fun file_name units_required =
+let link_archive output_fun currpos_fun file_name units_required =
   let inchan = open_in_bin file_name in
   try
     List.iter
       (fun cu ->
          let name = file_name ^ "(" ^ cu.cu_name ^ ")" in
          try
-           link_compunit ppf output_fun currpos_fun inchan name cu
+           link_compunit output_fun currpos_fun inchan name cu
          with Symtable.Error msg ->
            raise(Error(Symbol_error(name, msg))))
       units_required;
@@ -259,11 +259,11 @@ let link_archive ppf output_fun currpos_fun file_name units_required =
 
 (* Link in a .cmo or .cma file *)
 
-let link_file ppf output_fun currpos_fun = function
+let link_file output_fun currpos_fun = function
     Link_object(file_name, unit) ->
-      link_object ppf output_fun currpos_fun file_name unit
+      link_object output_fun currpos_fun file_name unit
   | Link_archive(file_name, units) ->
-      link_archive ppf output_fun currpos_fun file_name units
+      link_archive output_fun currpos_fun file_name units
 
 (* Output the debugging information *)
 (* Format is:
@@ -298,7 +298,7 @@ let make_absolute file =
 
 (* Create a bytecode executable file *)
 
-let link_bytecode ppf tolink exec_name standalone =
+let link_bytecode tolink exec_name standalone =
   (* Avoid the case where the specified exec output file is the same as
      one of the objects to be linked *)
   List.iter (function
@@ -343,7 +343,7 @@ let link_bytecode ppf tolink exec_name standalone =
     end;
     let output_fun = output_bytes outchan
     and currpos_fun () = pos_out outchan - start_code in
-    List.iter (link_file ppf output_fun currpos_fun) tolink;
+    List.iter (link_file output_fun currpos_fun) tolink;
     if check_dlls then Dll.close_all_dlls();
     (* The final STOP instruction *)
     output_byte outchan Opcodes.opSTOP;
@@ -444,7 +444,7 @@ let output_cds_file outfile =
 
 (* Output a bytecode executable as a C file *)
 
-let link_bytecode_as_c ppf tolink outfile =
+let link_bytecode_as_c tolink outfile =
   let outchan = open_out outfile in
   begin try
     (* The bytecode *)
@@ -464,7 +464,7 @@ let link_bytecode_as_c ppf tolink outfile =
       output_code_string outchan code;
       currpos := !currpos + Bytes.length code
     and currpos_fun () = !currpos in
-    List.iter (link_file ppf output_fun currpos_fun) tolink;
+    List.iter (link_file output_fun currpos_fun) tolink;
     (* The final STOP instruction *)
     Printf.fprintf outchan "\n0x%x};\n\n" Opcodes.opSTOP;
     (* The table of global data *)
@@ -565,7 +565,7 @@ let fix_exec_name name =
 
 (* Main entry point (build a custom runtime if needed) *)
 
-let link ppf objfiles output_name =
+let link objfiles output_name =
   let objfiles =
     if !Clflags.nopervasives then objfiles
     else if !Clflags.output_c_object then "stdlib.cma" :: objfiles
@@ -584,7 +584,7 @@ let link ppf objfiles output_name =
                                                    (* put user's opts first *)
   Clflags.dllibs := !lib_dllibs @ !Clflags.dllibs; (* put user's DLLs first *)
   if not !Clflags.custom_runtime then
-    link_bytecode ppf tolink output_name true
+    link_bytecode tolink output_name true
   else if not !Clflags.output_c_object then begin
     let bytecode_name = Filename.temp_file "camlcode" "" in
     let prim_name =
@@ -593,7 +593,7 @@ let link ppf objfiles output_name =
       else
         Filename.temp_file "camlprim" ".c" in
     try
-      link_bytecode ppf tolink bytecode_name false;
+      link_bytecode tolink bytecode_name false;
       let poc = open_out prim_name in
       (* note: builds will not be reproducible if the C code contains macros
          such as __FILE__. *)
@@ -646,7 +646,7 @@ let link ppf objfiles output_name =
       else basename ^ Config.ext_obj
     in
     try
-      link_bytecode_as_c ppf tolink c_file;
+      link_bytecode_as_c tolink c_file;
       if not (Filename.check_suffix output_name ".c") then begin
         temps := c_file :: !temps;
         if Ccomp.compile_file ~output:obj_file ?stable_name c_file <> 0 then
diff --git a/bytecomp/bytelink.mli b/bytecomp/bytelink.mli
index 56439e26c..e3cf98dad 100644
--- a/bytecomp/bytelink.mli
+++ b/bytecomp/bytelink.mli
@@ -15,11 +15,10 @@
 
 (* Link .cmo files and produce a bytecode executable. *)
 
-val link : Format.formatter -> string list -> string -> unit
+val link : string list -> string -> unit
 val reset : unit -> unit
 
-val check_consistency:
-  Format.formatter -> string -> Cmo_format.compilation_unit -> unit
+val check_consistency: string -> Cmo_format.compilation_unit -> unit
 
 val extract_crc_interfaces: unit -> (string * Digest.t option) list
 
diff --git a/bytecomp/bytepackager.ml b/bytecomp/bytepackager.ml
index ac78c3443..4cb13e064 100644
--- a/bytecomp/bytepackager.ml
+++ b/bytecomp/bytepackager.ml
@@ -132,11 +132,11 @@ let read_member_info file = (
    Accumulate relocs, debug info, etc.
    Return size of bytecode. *)
 
-let rename_append_bytecode ppf packagename oc mapping defined ofs prefix subst
+let rename_append_bytecode packagename oc mapping defined ofs prefix subst
                            objfile compunit =
   let ic = open_in_bin objfile in
   try
-    Bytelink.check_consistency ppf objfile compunit;
+    Bytelink.check_consistency objfile compunit;
     List.iter
       (rename_relocation packagename objfile mapping defined ofs)
       compunit.cu_reloc;
@@ -161,7 +161,7 @@ let rename_append_bytecode ppf packagename oc mapping defined ofs prefix subst
 (* Same, for a list of .cmo and .cmi files.
    Return total size of bytecode. *)
 
-let rec rename_append_bytecode_list ppf packagename oc mapping defined ofs
+let rec rename_append_bytecode_list packagename oc mapping defined ofs
                                     prefix subst =
   function
     [] ->
@@ -169,15 +169,15 @@ let rec rename_append_bytecode_list ppf packagename oc mapping defined ofs
   | m :: rem ->
       match m.pm_kind with
       | PM_intf ->
-          rename_append_bytecode_list ppf packagename oc mapping defined ofs
+          rename_append_bytecode_list packagename oc mapping defined ofs
                                       prefix subst rem
       | PM_impl compunit ->
           let size =
-            rename_append_bytecode ppf packagename oc mapping defined ofs
+            rename_append_bytecode packagename oc mapping defined ofs
                                    prefix subst m.pm_file compunit in
           let id = Ident.create_persistent m.pm_name in
           let root = Path.Pident (Ident.create_persistent prefix) in
-          rename_append_bytecode_list ppf packagename oc mapping (id :: defined)
+          rename_append_bytecode_list packagename oc mapping (id :: defined)
             (ofs + size) prefix
             (Subst.add_module id (Path.Pdot (root, Ident.name id, Path.nopos))
                               subst)
@@ -206,7 +206,7 @@ let build_global_target oc target_name members mapping pos coercion =
 
 (* Build the .cmo file obtained by packaging the given .cmo files. *)
 
-let package_object_files ppf files targetfile targetname coercion =
+let package_object_files files targetfile targetname coercion =
   let members =
     map_left_right read_member_info files in
   let required_globals =
@@ -241,7 +241,7 @@ let package_object_files ppf files targetfile targetname coercion =
     let pos_depl = pos_out oc in
     output_binary_int oc 0;
     let pos_code = pos_out oc in
-    let ofs = rename_append_bytecode_list ppf targetname oc mapping [] 0
+    let ofs = rename_append_bytecode_list targetname oc mapping [] 0
                                           targetname Subst.identity members in
     build_global_target oc targetname members mapping ofs coercion;
     let pos_debug = pos_out oc in
@@ -278,7 +278,7 @@ let package_object_files ppf files targetfile targetname coercion =
 
 (* The entry point *)
 
-let package_files ppf initial_env files targetfile =
+let package_files initial_env files targetfile =
     let files =
     List.map
         (fun f ->
@@ -291,7 +291,7 @@ let package_files ppf initial_env files targetfile =
     try
       let coercion =
         Typemod.package_units initial_env files targetcmi targetname in
-      package_object_files ppf files targetfile targetname coercion
+      package_object_files files targetfile targetname coercion
     with x ->
       remove_file targetfile; raise x
 
diff --git a/bytecomp/bytepackager.mli b/bytecomp/bytepackager.mli
index c856b632c..ae8663a67 100644
--- a/bytecomp/bytepackager.mli
+++ b/bytecomp/bytepackager.mli
@@ -16,7 +16,7 @@
 (* "Package" a set of .cmo files into one .cmo file having the
    original compilation units as sub-modules. *)
 
-val package_files: Format.formatter -> Env.t -> string list -> string -> unit
+val package_files: Env.t -> string list -> string -> unit
 
 type error =
     Forward_reference of string * Ident.t
diff --git a/driver/compmisc.ml b/driver/compmisc.ml
index 9177076ac..2869db0d4 100644
--- a/driver/compmisc.ml
+++ b/driver/compmisc.ml
@@ -57,11 +57,11 @@ let initial_env () =
     ~initially_opened_module
     ~open_implicit_modules:(List.rev !Clflags.open_modules)
 
-let read_color_env ppf =
+let read_color_env () =
   try
     match Clflags.parse_color_setting (Sys.getenv "OCAML_COLOR") with
     | None ->
-        Location.print_warning Location.none ppf
+        Location.prerr_warning Location.none
           (Warnings.Bad_env_variable
              ("OCAML_COLOR",
               "expected \"auto\", \"always\" or \"never\""));
diff --git a/driver/compmisc.mli b/driver/compmisc.mli
index 3dbcdaebd..fb29ff57c 100644
--- a/driver/compmisc.mli
+++ b/driver/compmisc.mli
@@ -16,4 +16,4 @@
 val init_path : ?dir:string -> bool -> unit
 val initial_env : unit -> Env.t
 
-val read_color_env : Format.formatter -> unit
+val read_color_env : unit -> unit
diff --git a/driver/main.ml b/driver/main.ml
index a9a7e1650..e9567a46f 100644
--- a/driver/main.ml
+++ b/driver/main.ml
@@ -134,7 +134,7 @@ let main () =
   try
     readenv ppf Before_args;
     Clflags.parse_arguments anonymous usage;
-    Compmisc.read_color_env ppf;
+    Compmisc.read_color_env ();
     begin try
       Compenv.process_deferred_actions
         (ppf,
@@ -162,8 +162,7 @@ let main () =
     if !make_archive then begin
       Compmisc.init_path false;
 
-      Bytelibrarian.create_archive ppf
-                                   (Compenv.get_objfiles ~with_ocamlparam:false)
+      Bytelibrarian.create_archive (Compenv.get_objfiles ~with_ocamlparam:false)
                                    (extract_output !output_name);
       Warnings.check_fatal ();
     end
@@ -171,7 +170,7 @@ let main () =
       Compmisc.init_path false;
       let extracted_output = extract_output !output_name in
       let revd = get_objfiles ~with_ocamlparam:false in
-      Bytepackager.package_files ppf (Compmisc.initial_env ())
+      Bytepackager.package_files (Compmisc.initial_env ())
         revd (extracted_output);
       Warnings.check_fatal ();
     end
@@ -193,7 +192,7 @@ let main () =
           default_output !output_name
       in
       Compmisc.init_path false;
-      Bytelink.link ppf (get_objfiles ~with_ocamlparam:true) target;
+      Bytelink.link (get_objfiles ~with_ocamlparam:true) target;
       Warnings.check_fatal ();
     end;
   with x ->
diff --git a/driver/optmain.ml b/driver/optmain.ml
index 7ae30b28b..0255e8fea 100644
--- a/driver/optmain.ml
+++ b/driver/optmain.ml
@@ -247,7 +247,7 @@ let main () =
        "<options> Compute dependencies \
         (use 'ocamlopt -depend -help' for details)"];
     Clflags.parse_arguments anonymous usage;
-    Compmisc.read_color_env ppf;
+    Compmisc.read_color_env ();
     if !gprofile && not Config.profiling then
       fatal "Profiling with \"gprof\" is not supported on this platform.";
     begin try
diff --git a/middle_end/middle_end.ml b/middle_end/middle_end.ml
index 457efde03..b3461f18c 100644
--- a/middle_end/middle_end.ml
+++ b/middle_end/middle_end.ml
@@ -45,11 +45,11 @@ let middle_end ppf ~prefixname ~backend
       end)
     in
     let warning_set = ref WarningSet.empty in
-    let flambda_warning_printer loc _fmt w =
+    let flambda_warning_printer loc ppf w =
       let elt = loc, w in
       if not (WarningSet.mem elt !warning_set) then begin
         warning_set := WarningSet.add elt !warning_set;
-        previous_warning_printer loc !Location.formatter_for_warnings w
+        previous_warning_printer loc ppf w
       end;
     in
     Misc.protect_refs