diff --git a/.github/workflows/build-others.yml b/.github/workflows/build-others.yml
index e449c5b042..5f670b2c4f 100644
--- a/.github/workflows/build-others.yml
+++ b/.github/workflows/build-others.yml
@@ -35,7 +35,8 @@ jobs:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}
 
       - name: Opam dependencies
-        run: opam install --deps-only -t .
+        run: |
+          opam install -y --deps-only -t ./ocamlformat-lib.opam ./ocamlformat.opam ./ocamlformat-rpc-lib.opam
 
       - name: Format
         run: opam exec -- dune fmt
diff --git a/lib/Conf_decl.ml b/lib/Conf_decl.ml
index aedceffd27..d9065a9524 100644
--- a/lib/Conf_decl.ml
+++ b/lib/Conf_decl.ml
@@ -171,7 +171,7 @@ let pp_from_src fs = function
         | `File loc -> ("file", loc)
         | `Attribute loc -> ("attribute", loc)
       in
-      let fname = Fpath.to_string ~relativize:true (Fpath.v pos_fname) in
+      let fname = normalized_path_to_string (Fpath.v pos_fname) in
       Format.fprintf fs " (%s %s:%i)" kind fname pos_lnum
   | `Env -> Format.fprintf fs " (environment variable)"
   | `Commandline -> Format.fprintf fs " (command line)"
diff --git a/lib/bin_conf/Bin_conf.ml b/lib/bin_conf/Bin_conf.ml
index 5c357c4a5a..7d3eb57330 100644
--- a/lib/bin_conf/Bin_conf.ml
+++ b/lib/bin_conf/Bin_conf.ml
@@ -539,9 +539,15 @@ let update_using_cmdline config =
   | Ok (`Ok conf_modif) -> conf_modif config
   | Error _ | Ok (`Version | `Help) -> config
 
+let path_to_absolute f =
+  let f =
+    if Fpath.is_rel f then Fpath.append (Fpath.v (Stdlib.Sys.getcwd ())) f
+    else f
+  in
+  Fpath.normalize f
+
 let build_config ~enable_outside_detected_project ~root ~file ~is_stdin =
-  let vfile = Fpath.v file in
-  let file_abs = Fpath.(vfile |> to_absolute |> normalize) in
+  let file_abs = path_to_absolute (Fpath.v file) in
   let fs =
     File_system.make ~enable_outside_detected_project
       ~disable_conf_files:!global_conf.disable_conf_files
@@ -579,7 +585,7 @@ let build_config ~enable_outside_detected_project ~root ~file ~is_stdin =
        | Some root ->
            Format.sprintf
              "no [.ocamlformat] was found within the project (root: %s)"
-             (Fpath.to_string ~relativize:true root)
+             (normalized_path_to_string root)
        | None -> "no project root was found"
      in
      warn ~loc:(Location.in_file file)
@@ -598,7 +604,7 @@ let build_config ~enable_outside_detected_project ~root ~file ~is_stdin =
           if conf.opr_opts.disable.v then "enabled" else "ignored"
         in
         if conf.opr_opts.debug.v then
-          warn ~loc "%a is %s." Fpath.pp file_abs status ;
+          warn ~loc "%s is %s." (normalized_path_to_string file_abs) status ;
         Operational.update conf ~f:(fun f ->
             {f with disable= {f.disable with v= not f.disable.v}} )
     | None -> conf
@@ -745,8 +751,7 @@ let validate_action () =
 
 let validate () =
   let root =
-    Option.map !global_conf.root
-      ~f:Fpath.(fun x -> v x |> to_absolute |> normalize)
+    Option.map !global_conf.root ~f:Fpath.(fun x -> path_to_absolute (v x))
   in
   let enable_outside_detected_project =
     !global_conf.enable_outside_detected_project && Option.is_none root
diff --git a/lib/bin_conf/File_system.ml b/lib/bin_conf/File_system.ml
index 04c4b82f50..13b4289aee 100644
--- a/lib/bin_conf/File_system.ml
+++ b/lib/bin_conf/File_system.ml
@@ -11,12 +11,14 @@
 
 let project_root_witness = [".git"; ".hg"; "dune-project"]
 
+let file_exists p = Stdlib.Sys.file_exists (Fpath.to_string p)
+
 let is_project_root ~root dir =
   match root with
   | Some root -> Fpath.equal dir root
   | None ->
       List.exists project_root_witness ~f:(fun name ->
-          Fpath.(exists (dir / name)) )
+          file_exists Fpath.(dir / name) )
 
 let dot_ocp_indent = ".ocp-indent"
 
@@ -29,7 +31,9 @@ let dot_ocamlformat_enable = ".ocamlformat-enable"
 type configuration_file = Ocamlformat of Fpath.t | Ocp_indent of Fpath.t
 
 let root_ocamlformat_file ~root =
-  let root = Option.value root ~default:(Fpath.cwd ()) in
+  let root =
+    match root with Some p -> p | None -> Fpath.v (Stdlib.Sys.getcwd ())
+  in
   Fpath.(root / dot_ocamlformat)
 
 let xdg_config () =
@@ -44,7 +48,7 @@ let xdg_config () =
   match xdg_config_home with
   | Some xdg_config_home ->
       let filename = Fpath.(xdg_config_home / "ocamlformat") in
-      if Fpath.exists filename then Some filename else None
+      if file_exists filename then Some filename else None
   | None -> None
 
 type t =
@@ -69,24 +73,24 @@ let make ~enable_outside_detected_project ~disable_conf_files
           { fs with
             ignore_files=
               (let filename = Fpath.(dir / dot_ocamlformat_ignore) in
-               if Fpath.exists filename then filename :: fs.ignore_files
+               if file_exists filename then filename :: fs.ignore_files
                else fs.ignore_files )
           ; enable_files=
               (let filename = Fpath.(dir / dot_ocamlformat_enable) in
-               if Fpath.exists filename then filename :: fs.enable_files
+               if file_exists filename then filename :: fs.enable_files
                else fs.enable_files )
           ; configuration_files=
               ( if disable_conf_files then []
                 else
                   let f_1 = Fpath.(dir / dot_ocamlformat) in
                   let files =
-                    if Fpath.exists f_1 then
+                    if file_exists f_1 then
                       Ocamlformat f_1 :: fs.configuration_files
                     else fs.configuration_files
                   in
                   if ocp_indent_config then
                     let f_2 = Fpath.(dir / dot_ocp_indent) in
-                    if Fpath.exists f_2 then Ocp_indent f_2 :: files
+                    if file_exists f_2 then Ocp_indent f_2 :: files
                     else files
                   else files ) }
         in
diff --git a/test/cli/global_configuration.t b/test/cli/global_configuration.t
index 33ede5db20..529f4d1896 100644
--- a/test/cli/global_configuration.t
+++ b/test/cli/global_configuration.t
@@ -1,7 +1,7 @@
 The user's global configuration should be used when [--enable-outside-detected-project] is passed.
 
   $ mkdir -p root xdg
-  $ export XDG_CONFIG_HOME=$PWD/xdg
+  $ export XDG_CONFIG_HOME=../xdg
   $ echo 'break-cases = vertical' > xdg/ocamlformat
 
   $ cd root
diff --git a/vendor/ocamlformat-stdlib/fpath_ext.ml b/vendor/ocamlformat-stdlib/fpath_ext.ml
deleted file mode 100644
index 1afde26e55..0000000000
--- a/vendor/ocamlformat-stdlib/fpath_ext.ml
+++ /dev/null
@@ -1,16 +0,0 @@
-include Fpath
-
-let cwd () = Stdlib.Sys.getcwd () |> v
-
-let exists p = to_string p |> Stdlib.Sys.file_exists
-
-let to_absolute file = if is_rel file then append (cwd ()) file else file
-
-let to_string ?(relativize = false) p =
-  if relativize then
-    Base.Option.value_map
-      (Fpath.relativize ~root:(cwd ()) p)
-      ~default:(to_string p) ~f:to_string
-  else to_string p
-
-let pp fmt p = Format.fprintf fmt "%s" (to_string ~relativize:true p)
diff --git a/vendor/ocamlformat-stdlib/fpath_ext.mli b/vendor/ocamlformat-stdlib/fpath_ext.mli
deleted file mode 100644
index 8c1f3277e6..0000000000
--- a/vendor/ocamlformat-stdlib/fpath_ext.mli
+++ /dev/null
@@ -1,17 +0,0 @@
-include module type of Fpath
-
-val cwd : unit -> t
-(** Current working directory. *)
-
-val exists : t -> bool
-(** [exists p] returns whether the given path [p] exists. *)
-
-val to_absolute : t -> t
-(** [to_absolute p] returns [cwd]/[p] if the [p] is relative, otherwise
-    returns [p]. *)
-
-val to_string : ?relativize:bool -> t -> string
-(** If [relativize] is set to [true] (it is set to [false] by default), the
-    path is relativized according to the [cwd]. *)
-
-val pp : Format.formatter -> t -> unit
diff --git a/vendor/ocamlformat-stdlib/ocamlformat_stdlib.ml b/vendor/ocamlformat-stdlib/ocamlformat_stdlib.ml
index 9e86c77264..8c17a6443a 100644
--- a/vendor/ocamlformat-stdlib/ocamlformat_stdlib.ml
+++ b/vendor/ocamlformat-stdlib/ocamlformat_stdlib.ml
@@ -1,13 +1,18 @@
 include Base
 include Stdio
 
-module Fpath = Fpath_ext
+module Fpath = Fpath
 module List = List_ext
 module String = String_ext
 module Warning = Warning
 module Format = Stdlib.Format
 module Filename = Stdlib.Filename
 
+let normalized_path_to_string p =
+  let cwd = Fpath.v (Stdlib.Sys.getcwd ()) in
+  let p = match Fpath.relativize ~root:cwd p with Some p -> p | None -> p in
+  fst (Fpath.split_volume p) ^ String.concat ~sep:"/" (Fpath.segs p)
+
 let ( >> ) f g x = g (f x)
 
 let impossible msg = failwith msg
diff --git a/vendor/ocamlformat-stdlib/ocamlformat_stdlib.mli b/vendor/ocamlformat-stdlib/ocamlformat_stdlib.mli
index fec28646c2..1a4278ba32 100644
--- a/vendor/ocamlformat-stdlib/ocamlformat_stdlib.mli
+++ b/vendor/ocamlformat-stdlib/ocamlformat_stdlib.mli
@@ -1,12 +1,15 @@
 include module type of Base
 include module type of Stdio
-module Fpath = Fpath_ext
 module List = List_ext
 module String = String_ext
 module Warning = Warning
 module Format = Stdlib.Format
 module Filename = Stdlib.Filename
 
+val normalized_path_to_string : Fpath.t -> string
+(** Render a path relative to the current directory using [/] as
+    separator on every platforms to ensure reproducible output in tests. *)
+
 val ( >> ) : ('a -> 'b) -> ('b -> 'c) -> 'a -> 'c
 (** Composition of functions: [(f >> g) x] is exactly equivalent to
     [g (f (x))]. Left associative. *)