diff --git a/src/driver/compile.ml b/src/driver/compile.ml
index d42154fa4a..1eace17a98 100644
--- a/src/driver/compile.ml
+++ b/src/driver/compile.ml
@@ -1,5 +1,7 @@
 (* compile *)
 
+open Bos
+
 type compiled = Odoc_unit.t
 
 let mk_byhash (pkgs : Odoc_unit.t list) =
@@ -22,7 +24,11 @@ let init_stats (units : Odoc_unit.t list) =
         let assets =
           match unit.kind with `Asset -> assets + 1 | _ -> assets
         in
-        let indexes = Fpath.Set.add unit.index.output_file indexes in
+        let indexes =
+          match unit.index with
+          | None -> indexes
+          | Some index -> Fpath.Set.add index.output_file indexes
+        in
         let non_hidden =
           match unit.kind with
           | `Intf { hidden = false; _ } -> non_hidden + 1
@@ -54,8 +60,7 @@ let unmarshal filename : partial =
     (fun () -> Marshal.from_channel ic)
 
 let marshal (v : partial) filename =
-  let p = Fpath.parent filename in
-  Util.mkdir_p p;
+  let _ = OS.Dir.create (Fpath.parent filename) |> Result.get_ok in
   let oc = open_out_bin (Fpath.to_string filename) in
   Fun.protect
     ~finally:(fun () -> close_out oc)
@@ -65,10 +70,10 @@ let find_partials odoc_dir : Odoc_unit.intf Odoc_unit.unit Util.StringMap.t * _
     =
   let tbl = Hashtbl.create 1000 in
   let hashes_result =
-    Bos.OS.Dir.fold_contents ~dotfiles:false ~elements:`Dirs
+    OS.Dir.fold_contents ~dotfiles:false ~elements:`Dirs
       (fun p hashes ->
         let index_m = Fpath.( / ) p "index.m" in
-        match Bos.OS.File.exists index_m with
+        match OS.File.exists index_m with
         | Ok true ->
             let tbl', hashes' = unmarshal index_m in
             List.iter
@@ -216,12 +221,13 @@ let sherlodoc_index_one ~output_dir (index : Odoc_unit.index) =
   let rel_path = Fpath.(index.search_dir / "sherlodoc_db.js") in
   let dst = Fpath.(output_dir // rel_path) in
   let dst_dir, _ = Fpath.split_base dst in
-  Util.mkdir_p dst_dir;
+  let _ = OS.Dir.create dst_dir |> Result.get_ok in
   Sherlodoc.index ~format:`js ~inputs ~dst ();
   rel_path
 
 let html_generate output_dir linked =
   let tbl = Hashtbl.create 10 in
+  let _ = OS.Dir.create output_dir |> Result.get_ok in
   Sherlodoc.js Fpath.(output_dir // Sherlodoc.js_file);
   let compile_index : Odoc_unit.index -> _ =
    fun index ->
@@ -256,10 +262,16 @@ let html_generate output_dir linked =
         Odoc.html_generate_asset ~output_dir ~input_file:l.odoc_file
           ~asset_path:l.input_file ()
     | _ ->
-        let db_path = compile_index l.index in
-        let search_uris = [ db_path; Sherlodoc.js_file ] in
-        let index = l.index.output_file in
-        Odoc.html_generate ~search_uris ~index ~output_dir ~input_file ();
+        let search_uris, index =
+          match l.index with
+          | None -> (None, None)
+          | Some index ->
+              let db_path = compile_index index in
+              let search_uris = [ db_path; Sherlodoc.js_file ] in
+              let index = index.output_file in
+              (Some search_uris, Some index)
+        in
+        Odoc.html_generate ?search_uris ?index ~output_dir ~input_file ();
         Atomic.incr Stats.stats.generated_units
   in
   Fiber.List.iter html_generate linked
diff --git a/src/driver/dune b/src/driver/dune
index 2f861500b2..b65a7f2a62 100644
--- a/src/driver/dune
+++ b/src/driver/dune
@@ -13,4 +13,5 @@
   opam-format
   logs
   logs.fmt
-  eio_main))
+  eio_main
+  odoc_utils))
diff --git a/src/driver/landing_pages.ml b/src/driver/landing_pages.ml
new file mode 100644
index 0000000000..eca5d59aa2
--- /dev/null
+++ b/src/driver/landing_pages.ml
@@ -0,0 +1,125 @@
+open Packages
+open Odoc_unit
+
+let fpf = Format.fprintf
+
+let make_unit ~odoc_dir ~odocl_dir ~mld_dir ~output_dir rel_path ~content
+    ?(include_dirs = []) ~pkgname ~pkg_args () =
+  let input_file = Fpath.(mld_dir // rel_path / "index.mld") in
+  let odoc_file = Fpath.(odoc_dir // rel_path / "page-index.odoc") in
+  let odocl_file = Fpath.(odocl_dir // rel_path / "page-index.odocl") in
+  Util.with_out_to input_file (fun oc ->
+      fpf (Format.formatter_of_out_channel oc) "%t@?" content)
+  |> Result.get_ok;
+  let parent_id = rel_path |> Odoc.Id.of_fpath in
+  {
+    parent_id;
+    odoc_dir;
+    input_file;
+    output_dir;
+    odoc_file;
+    odocl_file;
+    pkg_args;
+    pkgname;
+    include_dirs;
+    index = None;
+    kind = `Mld;
+  }
+
+module PackageLanding = struct
+  let content pkg ppf =
+    fpf ppf "{0 %s}\n" pkg.name;
+    if not (List.is_empty pkg.mlds) then
+      fpf ppf
+        "{1 Documentation pages}@\n@\n{{!/%s/doc/index}Documentation for %s}@\n"
+        pkg.name pkg.name;
+    if not (List.is_empty pkg.libraries) then
+      fpf ppf "{1 Libraries}@\n@\n{{!/%s/lib/index}Libraries for %s}@\n"
+        pkg.name pkg.name
+
+  let page ~odoc_dir ~odocl_dir ~mld_dir ~output_dir ~pkg =
+    let content = content pkg in
+    let rel_path = Fpath.v pkg.name in
+    let pkg_args =
+      { pages = [ (pkg.name, Fpath.( // ) odoc_dir rel_path) ]; libs = [] }
+    in
+    make_unit ~odoc_dir ~odocl_dir ~mld_dir ~output_dir rel_path ~content
+      ~pkgname:pkg.name ~pkg_args ()
+end
+
+module PackageList = struct
+  let content all ppf =
+    let sorted_packages =
+      all |> List.sort (fun n1 n2 -> String.compare n1.name n2.name)
+    in
+    fpf ppf "{0 List of all packages}@\n";
+    let print_pkg pkg =
+      fpf ppf "- {{!/__driver/%s/index}%s}@\n" pkg.name pkg.name
+    in
+    List.iter print_pkg sorted_packages
+
+  let page ~mld_dir ~odoc_dir ~odocl_dir ~output_dir all =
+    let content = content all in
+    let rel_path = Fpath.v "./" in
+    let pkgname = "__driver" in
+    let pkg_args =
+      { pages = [ (pkgname, Fpath.(odoc_dir // rel_path)) ]; libs = [] }
+    in
+    make_unit ~odoc_dir ~odocl_dir ~mld_dir ~output_dir ~content ~pkgname
+      ~pkg_args rel_path ()
+end
+
+module LibraryLanding = struct
+  let content lib ppf =
+    fpf ppf "{0 %s}@\n" lib.lib_name;
+    let print_module m =
+      if not m.m_hidden then fpf ppf "- {!%s}@\n" m.Packages.m_name
+    in
+    List.iter print_module lib.modules
+
+  let page ~pkg ~odoc_dir ~odocl_dir ~mld_dir ~output_dir lib =
+    let content = content lib in
+    let rel_path = Fpath.(v pkg.name / "lib" / lib.lib_name) in
+    let pkg_args =
+      { pages = [ (pkg.name, Fpath.( // ) odoc_dir rel_path) ]; libs = [] }
+    in
+    let include_dirs = [ Fpath.(odoc_dir // rel_path) ] in
+    make_unit ~odoc_dir ~odocl_dir ~mld_dir ~output_dir rel_path ~content
+      ~pkgname:pkg.name ~include_dirs ~pkg_args ()
+end
+
+module PackageLibLanding = struct
+  let content pkg ppf =
+    fpf ppf "{0 %s}@\n" pkg.name;
+    let print_lib (lib : Packages.libty) =
+      fpf ppf "- {{!/%s/%s/index}%s}@\n" pkg.name lib.lib_name lib.lib_name
+    in
+    List.iter print_lib pkg.libraries
+
+  let page ~pkg ~odoc_dir ~odocl_dir ~mld_dir ~output_dir =
+    let content = content pkg in
+    let rel_path = Fpath.(v pkg.name / "lib") in
+    let pkg_args =
+      { pages = [ (pkg.name, Fpath.( // ) odoc_dir rel_path) ]; libs = [] }
+    in
+    make_unit ~odoc_dir ~odocl_dir ~mld_dir ~output_dir rel_path ~content
+      ~pkgname:pkg.name ~pkg_args ()
+end
+
+let of_package ~mld_dir ~odoc_dir ~odocl_dir ~output_dir pkg =
+  let library_pages =
+    List.map
+      (LibraryLanding.page ~pkg ~odoc_dir ~odocl_dir ~mld_dir ~output_dir)
+      pkg.libraries
+  in
+  let package_landing_page =
+    PackageLanding.page ~odoc_dir ~odocl_dir ~mld_dir ~output_dir ~pkg
+  in
+  let library_list_page =
+    PackageLibLanding.page ~odoc_dir ~odocl_dir ~mld_dir ~output_dir ~pkg
+  in
+  package_landing_page :: library_list_page :: library_pages
+
+let of_packages ~mld_dir ~odoc_dir ~odocl_dir ~output_dir all =
+  PackageList.page ~mld_dir ~odoc_dir ~odocl_dir ~output_dir all
+  :: List.concat_map (of_package ~mld_dir ~odoc_dir ~odocl_dir ~output_dir) all
diff --git a/src/driver/landing_pages.mli b/src/driver/landing_pages.mli
new file mode 100644
index 0000000000..ee44cf1880
--- /dev/null
+++ b/src/driver/landing_pages.mli
@@ -0,0 +1,7 @@
+val of_packages :
+  mld_dir:Fpath.t ->
+  odoc_dir:Fpath.t ->
+  odocl_dir:Fpath.t ->
+  output_dir:Fpath.t ->
+  Packages.t list ->
+  [> `Mld ] Odoc_unit.unit list
diff --git a/src/driver/odoc.ml b/src/driver/odoc.ml
index aa5d9855e4..03edd03bc2 100644
--- a/src/driver/odoc.ml
+++ b/src/driver/odoc.ml
@@ -1,12 +1,20 @@
 open Bos
 
-type id = Fpath.t
+module Id : sig
+  type t
+  val to_fpath : t -> Fpath.t
+  val of_fpath : Fpath.t -> t
+  val to_string : t -> string
+end = struct
+  type t = Fpath.t
 
-let fpath_of_id id = id
+  let to_fpath id = id
 
-let id_of_fpath id =
-  id |> Fpath.normalize
-  |> Fpath.rem_empty_seg (* If an odoc path ends with a [/] everything breaks *)
+  let of_fpath id = id |> Fpath.normalize |> Fpath.rem_empty_seg
+  (* If an odoc path ends with a [/] everything breaks *)
+
+  let to_string id = match Fpath.to_string id with "." -> "" | v -> v
+end
 
 let index_filename = "index.odoc-index"
 
@@ -33,13 +41,13 @@ let compile ~output_dir ~input_file:file ~includes ~parent_id =
   in
   let output_file =
     let _, f = Fpath.split_base file in
-    Some Fpath.(output_dir // parent_id // set_ext "odoc" f)
+    Some Fpath.(output_dir // Id.to_fpath parent_id // set_ext "odoc" f)
   in
   let cmd =
     !odoc % "compile" % Fpath.to_string file % "--output-dir" % p output_dir
     %% includes % "--enable-missing-root-warning"
   in
-  let cmd = cmd % "--parent-id" % Fpath.to_string parent_id in
+  let cmd = cmd % "--parent-id" % Id.to_string parent_id in
   let desc = Printf.sprintf "Compiling %s" (Fpath.to_string file) in
   let lines = Cmd_outputs.submit desc cmd output_file in
   Cmd_outputs.(
@@ -48,13 +56,14 @@ let compile ~output_dir ~input_file:file ~includes ~parent_id =
 let compile_asset ~output_dir ~name ~parent_id =
   let open Cmd in
   let output_file =
-    Some Fpath.(output_dir // parent_id / ("asset-" ^ name ^ ".odoc"))
+    Some
+      Fpath.(output_dir // Id.to_fpath parent_id / ("asset-" ^ name ^ ".odoc"))
   in
   let cmd =
     !odoc % "compile-asset" % "--name" % name % "--output-dir" % p output_dir
   in
 
-  let cmd = cmd % "--parent-id" % Fpath.to_string parent_id in
+  let cmd = cmd % "--parent-id" % Id.to_string parent_id in
   let desc = Printf.sprintf "Compiling %s" name in
   let lines = Cmd_outputs.submit desc cmd output_file in
   Cmd_outputs.(add_prefixed_output cmd compile_output name lines)
@@ -73,10 +82,12 @@ let compile_impl ~output_dir ~input_file:file ~includes ~parent_id ~source_id =
   let output_file =
     let _, f = Fpath.split_base file in
     Some
-      Fpath.(output_dir // parent_id / ("impl-" ^ to_string (set_ext "odoc" f)))
+      Fpath.(
+        output_dir // Id.to_fpath parent_id
+        / ("impl-" ^ to_string (set_ext "odoc" f)))
   in
-  let cmd = cmd % "--parent-id" % Fpath.to_string parent_id in
-  let cmd = cmd % "--source-id" % Fpath.to_string source_id in
+  let cmd = cmd % "--parent-id" % Id.to_string parent_id in
+  let cmd = cmd % "--source-id" % Id.to_string source_id in
   let desc =
     Printf.sprintf "Compiling implementation %s" (Fpath.to_string file)
   in
diff --git a/src/driver/odoc.mli b/src/driver/odoc.mli
index 06ae01fcf3..6c45f940b6 100644
--- a/src/driver/odoc.mli
+++ b/src/driver/odoc.mli
@@ -1,7 +1,9 @@
-type id
-
-val fpath_of_id : id -> Fpath.t
-val id_of_fpath : Fpath.t -> id
+module Id : sig
+  type t
+  val to_fpath : t -> Fpath.t
+  val of_fpath : Fpath.t -> t
+  val to_string : t -> string
+end
 
 val index_filename : string
 
@@ -14,17 +16,17 @@ val compile_impl :
   output_dir:Fpath.t ->
   input_file:Fpath.t ->
   includes:Fpath.set ->
-  parent_id:id ->
-  source_id:id ->
+  parent_id:Id.t ->
+  source_id:Id.t ->
   unit
 val compile :
   output_dir:Fpath.t ->
   input_file:Fpath.t ->
   includes:Fpath.set ->
-  parent_id:id ->
+  parent_id:Id.t ->
   unit
 
-val compile_asset : output_dir:Fpath.t -> name:string -> parent_id:id -> unit
+val compile_asset : output_dir:Fpath.t -> name:string -> parent_id:Id.t -> unit
 
 val link :
   ?ignore_output:bool ->
diff --git a/src/driver/odoc_driver.ml b/src/driver/odoc_driver.ml
index 7d92dfc365..43738d265c 100644
--- a/src/driver/odoc_driver.ml
+++ b/src/driver/odoc_driver.ml
@@ -558,8 +558,17 @@ let run libs verbose packages_dir odoc_dir odocl_dir html_dir stats nb_workers
       (fun () ->
         let all =
           let all = Util.StringMap.bindings all |> List.map snd in
-          Odoc_unit.of_packages ~output_dir:odoc_dir ~linked_dir:odocl_dir
-            ~index_dir:None all
+          let internal =
+            Odoc_unit.of_packages ~output_dir:odoc_dir ~linked_dir:odocl_dir
+              ~index_dir:None all
+          in
+          let external_ =
+            let mld_dir = odoc_dir in
+            let odocl_dir = Option.value odocl_dir ~default:odoc_dir in
+            Landing_pages.of_packages ~mld_dir ~odoc_dir ~odocl_dir
+              ~output_dir:odoc_dir all
+          in
+          internal @ external_
         in
         Compile.init_stats all;
         let compiled =
diff --git a/src/driver/odoc_unit.ml b/src/driver/odoc_unit.ml
index 685dd5464e..66812f22b0 100644
--- a/src/driver/odoc_unit.ml
+++ b/src/driver/odoc_unit.ml
@@ -11,7 +11,7 @@ type index = {
 }
 
 type 'a unit = {
-  parent_id : Odoc.id;
+  parent_id : Odoc.Id.t;
   odoc_dir : Fpath.t;
   input_file : Fpath.t;
   output_dir : Fpath.t;
@@ -20,14 +20,14 @@ type 'a unit = {
   pkg_args : pkg_args;
   pkgname : string;
   include_dirs : Fpath.t list;
-  index : index;
+  index : index option;
   kind : 'a;
 }
 
 type intf_extra = { hidden : bool; hash : string; deps : intf unit list }
 and intf = [ `Intf of intf_extra ]
 
-type impl_extra = { src_id : Odoc.id; src_path : Fpath.t }
+type impl_extra = { src_id : Odoc.Id.t; src_path : Fpath.t }
 type impl = [ `Impl of impl_extra ]
 
 type mld = [ `Mld ]
@@ -96,7 +96,7 @@ let of_packages ~output_dir ~linked_dir ~index_dir (pkgs : Packages.t list) :
     let ( // ) = Fpath.( // ) in
     let ( / ) = Fpath.( / ) in
     let odoc_dir = output_dir // rel_dir in
-    let parent_id = rel_dir |> Odoc.id_of_fpath in
+    let parent_id = rel_dir |> Odoc.Id.of_fpath in
     let odoc_file = odoc_dir / (name ^ ".odoc") in
     let odocl_file = linked_dir // rel_dir / (name ^ ".odocl") in
     {
@@ -110,7 +110,7 @@ let of_packages ~output_dir ~linked_dir ~index_dir (pkgs : Packages.t list) :
       odocl_file;
       include_dirs;
       kind;
-      index = index_of pkg;
+      index = Some (index_of pkg);
     }
   in
   let rec build_deps deps =
@@ -152,7 +152,7 @@ let of_packages ~output_dir ~linked_dir ~index_dir (pkgs : Packages.t list) :
         let kind =
           let src_name = Fpath.filename src_path in
           let src_id =
-            Fpath.(pkg.pkg_dir / "src" / libname / src_name) |> Odoc.id_of_fpath
+            Fpath.(pkg.pkg_dir / "src" / libname / src_name) |> Odoc.Id.of_fpath
           in
           `Impl { src_id; src_path }
         in
diff --git a/src/driver/odoc_unit.mli b/src/driver/odoc_unit.mli
index be617ee12c..9da8701704 100644
--- a/src/driver/odoc_unit.mli
+++ b/src/driver/odoc_unit.mli
@@ -11,7 +11,7 @@ type index = {
 }
 
 type 'a unit = {
-  parent_id : Odoc.id;
+  parent_id : Odoc.Id.t;
   odoc_dir : Fpath.t;
   input_file : Fpath.t;
   output_dir : Fpath.t;
@@ -20,14 +20,14 @@ type 'a unit = {
   pkg_args : pkg_args;
   pkgname : string;
   include_dirs : Fpath.t list;
-  index : index;
+  index : index option;
   kind : 'a;
 }
 
 type intf_extra = { hidden : bool; hash : string; deps : intf unit list }
 and intf = [ `Intf of intf_extra ]
 
-type impl_extra = { src_id : Odoc.id; src_path : Fpath.t }
+type impl_extra = { src_id : Odoc.Id.t; src_path : Fpath.t }
 type impl = [ `Impl of impl_extra ]
 
 type mld = [ `Mld ]
diff --git a/src/driver/util.ml b/src/driver/util.ml
index 2fc786c226..a74f5a3774 100644
--- a/src/driver/util.ml
+++ b/src/driver/util.ml
@@ -1,3 +1,4 @@
+open Odoc_utils
 open Bos
 
 module StringSet = Set.Make (String)
@@ -17,29 +18,17 @@ let lines_of_process cmd =
   | Ok x -> x
   | Error (`Msg e) -> failwith ("Error: " ^ e)
 
-let mkdir_p d =
-  let segs =
-    Fpath.segs (Fpath.normalize d) |> List.filter (fun s -> String.length s > 0)
-  in
-  let _ =
-    List.fold_left
-      (fun path seg ->
-        let d = Fpath.(path // v seg) in
-        try
-          Unix.mkdir (Fpath.to_string d) 0o755;
-          d
-        with
-        | Unix.Unix_error (Unix.EEXIST, _, _) -> d
-        | exn -> raise exn)
-      (Fpath.v ".") segs
-  in
-  ()
-
-let write_file filename lines =
-  let dir = fst (Fpath.split_base filename) in
-  mkdir_p dir;
-  let oc = open_out (Fpath.to_string filename) in
-  List.iter (fun line -> Printf.fprintf oc "%s\n" line) lines;
-  close_out oc
+(** Opens a file for writing and calls [f]. The destination directory is created
+    if needed. *)
+let with_out_to filename f =
+  let open ResultMonad in
+  OS.Dir.create (Fpath.parent filename) >>= fun _ ->
+  OS.File.with_oc filename
+    (fun oc () ->
+      f oc;
+      Ok ())
+    ()
+  |> Result.join
+  >>= fun () -> Ok ()
 
 let cp src dst = assert (lines_of_process Cmd.(v "cp" % src % dst) = [])
diff --git a/src/html/link.ml b/src/html/link.ml
index ece4b8c001..871bcc12df 100644
--- a/src/html/link.ml
+++ b/src/html/link.ml
@@ -36,7 +36,9 @@ module Path = struct
     dir @ [ file ]
 
   let as_filename ~is_flat (url : Url.Path.t) =
-    Fpath.(v @@ String.concat Fpath.dir_sep @@ for_linking ~is_flat url)
+    let url_segs = for_linking ~is_flat url in
+    let filename = Fpath.(v @@ String.concat Fpath.dir_sep @@ url_segs) in
+    filename
 end
 
 type resolve = Current of Url.Path.t | Base of string
diff --git a/src/odoc/asset.ml b/src/odoc/asset.ml
index e38c1067f4..57222e26d9 100644
--- a/src/odoc/asset.ml
+++ b/src/odoc/asset.ml
@@ -1,12 +1,19 @@
+open Or_error
+
 let compile ~parent_id ~name ~output_dir =
   let open Odoc_model in
-  let parent_id = Compile.mk_id parent_id in
+  let parent_id =
+    match Compile.mk_id parent_id with
+    | Some s -> Ok s
+    | None -> Error (`Msg "parent-id cannot be empty when compiling assets.")
+  in
+  parent_id >>= fun parent_id ->
   let id =
     Paths.Identifier.Mk.asset_file
       ((parent_id :> Paths.Identifier.Page.t), Names.AssetName.make_std name)
   in
   let directory =
-    Compile.path_of_id output_dir parent_id
+    Compile.path_of_id output_dir (Some parent_id)
     |> Fpath.to_string |> Fs.Directory.of_string
   in
   let name = "asset-" ^ name ^ ".odoc" in
@@ -21,4 +28,4 @@ let compile ~parent_id ~name ~output_dir =
       }
   in
   let asset = Lang.Asset.{ name = id; root } in
-  Odoc_file.save_asset output ~warnings:[] asset
+  Ok (Odoc_file.save_asset output ~warnings:[] asset)
diff --git a/src/odoc/asset.mli b/src/odoc/asset.mli
index 157cbbcea8..8ac413ec54 100644
--- a/src/odoc/asset.mli
+++ b/src/odoc/asset.mli
@@ -1 +1,7 @@
-val compile : parent_id:string -> name:string -> output_dir:string -> unit
+open Or_error
+
+val compile :
+  parent_id:string ->
+  name:string ->
+  output_dir:string ->
+  (unit, [> msg ]) result
diff --git a/src/odoc/bin/main.ml b/src/odoc/bin/main.ml
index bc8ccccd81..8829f2efdd 100644
--- a/src/odoc/bin/main.ml
+++ b/src/odoc/bin/main.ml
@@ -353,7 +353,9 @@ module Compile_asset = struct
         & opt (some string) None
         & info ~docs ~docv:"PARENT" ~doc [ "parent-id" ])
     in
-    Term.(const compile_asset $ parent_id $ asset_name $ output_dir)
+    Term.(
+      const handle_error
+      $ (const compile_asset $ parent_id $ asset_name $ output_dir))
 
   let info ~docs =
     let man =
diff --git a/src/odoc/compile.ml b/src/odoc/compile.ml
index 09e59a68aa..26964733da 100644
--- a/src/odoc/compile.ml
+++ b/src/odoc/compile.ml
@@ -42,11 +42,13 @@ type spec = {
 }
 
 let rec path_of_id output_dir id =
-  match (id : Paths.Identifier.ContainerPage.t).iv with
-  | `Page (None, p) -> Fpath.(v output_dir / PageName.to_string p)
-  | `Page (Some parent, p) ->
-      let d = path_of_id output_dir parent in
-      Fpath.(d / PageName.to_string p)
+  match id with
+  | None -> Fpath.v output_dir
+  | Some id -> (
+      match (id : Paths.Identifier.ContainerPage.t).iv with
+      | `Page (parent, p) ->
+          let d = path_of_id output_dir parent in
+          Fpath.(d / PageName.to_string p))
 
 let check_is_empty msg = function [] -> Ok () | _ :: _ -> Error (`Msg msg)
 
@@ -95,13 +97,17 @@ let resolve_parent_page resolver f =
   extract_parent page.name >>= fun parent -> Ok (parent, page.children)
 
 let mk_id str =
-  let l = String.cuts ~sep:"/" str in
-  List.fold_left
-    (fun acc id -> Some (Paths.Identifier.Mk.page (acc, PageName.make_std id)))
-    None l
-  |> function
-  | Some x -> x
-  | None -> failwith "Failed to create ID"
+  match str with
+  | "" -> None
+  | str -> (
+      let l = String.cuts ~sep:"/" str in
+      List.fold_left
+        (fun acc id ->
+          Some (Paths.Identifier.Mk.page (acc, PageName.make_std id)))
+        None l
+      |> function
+      | Some x -> Some x
+      | None -> failwith "Failed to create ID")
 
 let resolve_imports resolver imports =
   List.map
@@ -300,13 +306,7 @@ let resolve_spec ~input resolver cli_spec =
         else name |> Fpath.to_string |> String.Ascii.uncapitalize
       in
       let output = Fs.File.create ~directory ~name in
-      Ok
-        {
-          parent_id = Some parent_id;
-          output;
-          parents_children = None;
-          children = [];
-        }
+      Ok { parent_id; output; parents_children = None; children = [] }
   | CliNoParent output ->
       Ok { output; parent_id = None; parents_children = None; children = [] }
 
diff --git a/src/odoc/compile.mli b/src/odoc/compile.mli
index dfa17159b0..4a82262e39 100644
--- a/src/odoc/compile.mli
+++ b/src/odoc/compile.mli
@@ -49,8 +49,9 @@ val resolve_parent_page :
 (** Parse and resolve a parent reference. Returns the identifier of the parent
     and its children as a list of reference. *)
 
-val mk_id : string -> Identifier.ContainerPage.t
-val path_of_id : string -> Comment.Identifier.Id.container_page -> Fpath.t
+val mk_id : string -> Identifier.ContainerPage.t option
+val path_of_id :
+  string -> Comment.Identifier.Id.container_page option -> Fpath.t
 
 val compile :
   resolver:Resolver.t ->
diff --git a/src/odoc/source.ml b/src/odoc/source.ml
index e2acb2c4ba..cd6ba6d35c 100644
--- a/src/odoc/source.ml
+++ b/src/odoc/source.ml
@@ -31,8 +31,14 @@ let compile ~resolver ~output ~warnings_options ~source_id input =
           Error (`Msg "Source id cannot be in the root directory")
         else
           let parent =
-            Compile.mk_id Fpath.(to_string (rem_empty_seg parent_id))
+            match Compile.mk_id Fpath.(to_string (rem_empty_seg parent_id)) with
+            | Some s -> Ok s
+            | None ->
+                Error
+                  (`Msg
+                    "parent-id cannot be empty when compiling implementations.")
           in
+          parent >>= fun parent ->
           let source_id =
             Paths.Identifier.Mk.source_page (parent, Fpath.to_string name)
           in
diff --git a/test/parent_id/dune b/test/parent_id/dune
index 36d06be450..3d43ccd34c 100644
--- a/test/parent_id/dune
+++ b/test/parent_id/dune
@@ -1,2 +1,7 @@
+(env
+ (_
+  (binaries
+   (../odoc_print/odoc_print.exe as odoc_print))))
+
 (cram
- (deps %{bin:odoc}))
+ (deps %{bin:odoc} %{bin:odoc_print}))
diff --git a/test/parent_id/empty_parent_id.t/run.t b/test/parent_id/empty_parent_id.t/run.t
new file mode 100644
index 0000000000..deaf1a95cd
--- /dev/null
+++ b/test/parent_id/empty_parent_id.t/run.t
@@ -0,0 +1,15 @@
+  $ echo "{0 Test}" > file.mld
+
+It is possible to have pages with no parent, even with the odoc 3 "parent-id"
+argument. In this case, an empty string is passed as argument.
+
+  $ odoc compile --parent-id "" --output-dir _odoc file.mld
+  $ ls _odoc
+  page-file.odoc
+  $ odoc_print _odoc/page-file.odoc | jq ".name"
+  {
+    "`LeafPage": [
+      "None",
+      "file"
+    ]
+  }