diff --git a/src/client/opamAdminCommand.ml b/src/client/opamAdminCommand.ml
index 38954d1c6b1..7b3947d0ffb 100644
--- a/src/client/opamAdminCommand.ml
+++ b/src/client/opamAdminCommand.ml
@@ -332,6 +332,25 @@ let packages_with_prefixes repo_root packages =
             (List.rev missing_pkgs)));
   pkgs_map
 
+let check_opam_file_version_url has_error repo_root prefix nv opam =
+  let min_opam_version = OpamVersion.of_string "2.0" in
+  let url_file =
+    let open OpamFilename.Op in
+    OpamFile.make
+      (OpamRepositoryPath.packages repo_root prefix nv // "url")
+  in
+  let opam_version = opam.OpamFile.OPAM.opam_version in
+  if OpamFile.exists url_file then
+    (OpamConsole.warning "Not updating external URL file at %s"
+       (OpamFile.to_string url_file);
+     true)
+  else if OpamVersion.compare opam_version min_opam_version < 0 then
+    (OpamConsole.warning "OPAM version must be >= 2.0 at %s"
+       (OpamFile.to_string (OpamRepositoryPath.opam repo_root prefix nv));
+     true)
+  else
+    has_error
+
 let update_extrafiles_command_doc =
   "Add extra-files to an opam repository."
 let update_extrafiles_command cli =
@@ -368,12 +387,7 @@ let update_extrafiles_command cli =
           let opam_file = OpamRepositoryPath.opam repo_root prefix nv in
           let opam = OpamFile.OPAM.read opam_file in
           let has_error =
-            if OpamFile.exists (OpamRepositoryPath.url repo_root prefix nv) then
-              (OpamConsole.warning "Not updating external URL file at %s"
-                 (OpamFile.to_string
-                    (OpamRepositoryPath.url repo_root prefix nv));
-               true)
-            else has_error
+            check_opam_file_version_url has_error repo_root prefix nv opam
           in
           let files_dir = OpamRepositoryPath.files repo_root prefix nv in
           if OpamFilename.exists_dir files_dir then
@@ -552,11 +566,7 @@ let add_hashes_command cli =
           let opam_file = OpamRepositoryPath.opam repo_root prefix nv in
           let opam = OpamFile.OPAM.read opam_file in
           let has_error =
-            if OpamFile.exists (OpamRepositoryPath.url repo_root prefix nv) then
-              (OpamConsole.warning "Not updating external URL file at %s"
-                 (OpamFile.to_string (OpamRepositoryPath.url repo_root prefix nv));
-               true)
-            else has_error
+            check_opam_file_version_url has_error repo_root prefix nv opam
           in
           let process_url has_error urlf =
             let hashes = OpamFile.URL.checksum urlf in
diff --git a/src/client/opamAdminRepoUpgrade.ml b/src/client/opamAdminRepoUpgrade.ml
index 84a12fae7f2..260df43bbac 100644
--- a/src/client/opamAdminRepoUpgrade.ml
+++ b/src/client/opamAdminRepoUpgrade.ml
@@ -217,7 +217,9 @@ let do_upgrade repo_root =
       let descr_file =
         OpamFilename.(opt_file (add_extension (chop_extension comp_file) "descr"))
       in
-      let descr = descr_file >>| fun f -> OpamFile.Descr.read (OpamFile.make f) in
+      let descr =
+        descr_file >>| fun f -> OpamFile.Descr.create (OpamFilename.read f)
+      in
       let nv, ocaml_version, variant =
         match OpamStd.String.cut_at c '+' with
         | None ->
@@ -428,11 +430,11 @@ let do_upgrade repo_root =
         in
         if opam <> opam0 then
           (OpamFile.OPAM.write_with_preserved_format opam_file opam;
+           let open OpamFilename.Op in
+           let path = OpamRepositoryPath.packages repo_root prefix package in
            List.iter OpamFilename.remove [
-             OpamFile.filename
-               (OpamRepositoryPath.descr repo_root prefix package);
-             OpamFile.filename
-               (OpamRepositoryPath.url repo_root prefix package);
+             OpamFile.filename (OpamFile.make (path // "descr"));
+             OpamFile.filename (OpamFile.make (path // "url"));
            ];
            OpamConsole.status_line "Updated %s" (OpamFile.to_string opam_file))
     )
diff --git a/src/client/opamPinCommand.ml b/src/client/opamPinCommand.ml
index 0dfa97051d3..7b706ad5372 100644
--- a/src/client/opamPinCommand.ml
+++ b/src/client/opamPinCommand.ml
@@ -259,12 +259,6 @@ let edit st ?version name =
     |  Some o when OpamFile.OPAM.equal opam o ->
       (OpamConsole.msg "Package metadata unchanged.\n"; st)
     | _ ->
-      (* Remove obsolete auxiliary files, in case *)
-      OpamFilename.remove
-        (OpamFile.filename (path OpamPath.Switch.Overlay.url));
-      OpamFilename.remove
-        (OpamFile.filename (path OpamPath.Switch.Overlay.descr));
-
       let opam_extra =
         OpamStd.Option.default [] @@ OpamFile.OPAM.extra_files opam
       in
diff --git a/src/format/opamFile.ml b/src/format/opamFile.ml
index 28707cc9658..614e2f703e7 100644
--- a/src/format/opamFile.ml
+++ b/src/format/opamFile.ml
@@ -186,10 +186,7 @@ end
     content. Formerly, (<repo>/packages/.../descr,
     <repo>/compilers/.../<v>.descr) *)
 
-module DescrIO = struct
-
-  let internal = "descr"
-  let format_version = OpamVersion.of_string "0"
+module Descr = struct
 
   type t = string * string
 
@@ -203,24 +200,6 @@ module DescrIO = struct
     | "" -> x ^ "\n"
     | y -> String.concat "" [x; "\n\n"; y; "\n"]
 
-  let of_channel _ ic =
-    let x =
-      try OpamStd.String.strip (input_line ic)
-      with End_of_file | Sys_error _ -> "" in
-    let y =
-      try OpamStd.String.strip (OpamSystem.string_of_channel ic)
-      with End_of_file | Sys_error _ -> ""
-    in
-    x, y
-
-  let to_channel _ oc (x,y) =
-    output_string oc x;
-    output_char oc '\n';
-    if y <> "" then
-      (output_char oc '\n';
-       output_string oc y;
-       output_char oc '\n')
-
   let create str =
     let head, tail =
       match OpamStd.String.cut_at str '\n' with
@@ -228,14 +207,6 @@ module DescrIO = struct
       | Some (h,t) -> h, t in
     OpamStd.String.strip head, OpamStd.String.strip tail
 
-  let of_string _ = create
-
-  let to_string _ = full
-
-end
-module Descr = struct
-  include DescrIO
-  include MakeIO(DescrIO)
 end
 
 (* module Comp_descr = Descr *)
@@ -3182,7 +3153,7 @@ module OPAMSyntax = struct
         Pp.V.os_constraint;
       "descr", no_cleanup Pp.ppacc_opt with_descr OpamStd.Option.none
         (Pp.V.string_tr -|
-         Pp.of_pair "descr" Descr.(of_string (), to_string ()));
+         Pp.of_pair "descr" Descr.(create, full));
       "extra-sources", no_cleanup Pp.ppacc_opt
         with_extra_sources OpamStd.Option.none
         (Pp.V.map_list ~depth:2 @@
diff --git a/src/format/opamFile.mli b/src/format/opamFile.mli
index 00d529c84a8..abd8b4e2d91 100644
--- a/src/format/opamFile.mli
+++ b/src/format/opamFile.mli
@@ -298,12 +298,11 @@ end
 (** Package descriptions: [$opam/descr/] *)
 module Descr: sig
 
-  include IO_FILE
+  type t
 
-  val create: string -> t
+  val empty : t
 
-  (** Create an abstract description file from a string *)
-  val of_string: t typed_file -> string -> t
+  val create: string -> t
 
   (** Return the first line *)
   val synopsis: t -> string
diff --git a/src/format/opamPath.ml b/src/format/opamPath.ml
index 2577dad21fd..625a41d1501 100644
--- a/src/format/opamPath.ml
+++ b/src/format/opamPath.ml
@@ -270,10 +270,6 @@ module Switch = struct
 
     let tmp_opam t a n = package t a n /- "opam_"
 
-    let url t a n = package t a n /- "url"
-
-    let descr t a n = package t a n /- "descr"
-
     let files t a n = package t a n / "files"
 
   end
diff --git a/src/format/opamPath.mli b/src/format/opamPath.mli
index 43a40e4862c..c853496f692 100644
--- a/src/format/opamPath.mli
+++ b/src/format/opamPath.mli
@@ -362,13 +362,6 @@ module Switch: sig
         $meta/overlay/$name.$version/opam_} *)
     val tmp_opam: t -> switch -> name -> OpamFile.OPAM.t OpamFile.t
 
-    (** URL overlay: {i
-        $meta/overlay/$name.$version/url} *)
-    val url: t -> switch -> name -> OpamFile.URL.t OpamFile.t
-
-    (** Descr orverlay *)
-    val descr: t -> switch -> name -> OpamFile.Descr.t OpamFile.t
-
     (** Files overlay *)
     val files: t -> switch -> name -> dirname
   end
diff --git a/src/repository/opamRepositoryPath.ml b/src/repository/opamRepositoryPath.ml
index ccc79df1bbb..bf70e0c21cb 100644
--- a/src/repository/opamRepositoryPath.ml
+++ b/src/repository/opamRepositoryPath.ml
@@ -44,12 +44,6 @@ let packages repo_root prefix nv =
 let opam repo_root prefix nv =
   packages repo_root prefix nv // "opam" |> OpamFile.make
 
-let descr repo_root prefix nv =
-  packages repo_root prefix nv // "descr" |> OpamFile.make
-
-let url repo_root prefix nv =
-  packages repo_root prefix nv // "url" |> OpamFile.make
-
 let files repo_root prefix nv =
   packages repo_root prefix nv / "files"
 
diff --git a/src/repository/opamRepositoryPath.mli b/src/repository/opamRepositoryPath.mli
index 1a24db0c844..1c2cf33a106 100644
--- a/src/repository/opamRepositoryPath.mli
+++ b/src/repository/opamRepositoryPath.mli
@@ -41,13 +41,6 @@ val packages: dirname -> string option -> package -> dirname
     {i $repo/packages/XXX/$NAME.$VERSION/opam} *)
 val opam: dirname -> string option -> package -> OpamFile.OPAM.t OpamFile.t
 
-(** Return the description file for a given package:
-    {i $repo/packages/XXX/$NAME.VERSION/descr} *)
-val descr: dirname -> string option -> package -> OpamFile.Descr.t OpamFile.t
-
-(** urls {i $repo/package/XXX/$NAME.$VERSION/url} *)
-val url: dirname -> string option -> package -> OpamFile.URL.t OpamFile.t
-
 (** files {i $repo/packages/XXX/$NAME.$VERSION/files} *)
 val files: dirname -> string option -> package -> dirname
 
diff --git a/src/state/opamFileTools.ml b/src/state/opamFileTools.ml
index c27ed93f5b7..eb08489abb6 100644
--- a/src/state/opamFileTools.ml
+++ b/src/state/opamFileTools.ml
@@ -1297,44 +1297,9 @@ let add_aux_files ?dir ?(files_subdir_hashes=false) opam =
   match dir with
   | None -> opam
   | Some dir ->
-    let (url_file: OpamFile.URL.t OpamFile.t) =
-      OpamFile.make (dir // "url")
-    in
-    let (descr_file: OpamFile.Descr.t OpamFile.t)  =
-      OpamFile.make (dir // "descr")
-    in
     let files_dir =
       OpamFilename.Op.(dir / "files")
     in
-    let opam =
-      match OpamFile.OPAM.url opam, try_read OpamFile.URL.read_opt url_file with
-      | None, (Some url, None) -> OpamFile.OPAM.with_url url opam
-      | Some opam_url, (Some url, errs) ->
-        if url = opam_url && errs = None then
-          log "Duplicate definition of url in '%s' and opam file"
-            (OpamFile.to_string url_file)
-        else
-          OpamConsole.warning
-            "File '%s' ignored (conflicting url already specified in the \
-             'opam' file)"
-            (OpamFile.to_string url_file);
-        opam
-      | _, (_, Some err) ->
-        OpamFile.OPAM.with_format_errors (err :: opam.format_errors) opam
-      | _, (None, None) -> opam
-    in
-    let opam =
-      match OpamFile.OPAM.descr opam,
-            try_read OpamFile.Descr.read_opt descr_file with
-      | None, (Some descr, None) -> OpamFile.OPAM.with_descr descr opam
-      | Some _, (Some _, _) ->
-        log "Duplicate descr in '%s' and opam file"
-          (OpamFile.to_string descr_file);
-        opam
-      | _, (_, Some err) ->
-        OpamFile.OPAM.with_format_errors (err :: opam.format_errors) opam
-      | _, (None, None)  -> opam
-    in
     let opam =
       let extra_files =
         OpamFilename.opt_dir files_dir >>| fun dir ->
diff --git a/src/state/opamFormatUpgrade.ml b/src/state/opamFormatUpgrade.ml
index d2304e5c4f6..71e08042bb9 100644
--- a/src/state/opamFormatUpgrade.ml
+++ b/src/state/opamFormatUpgrade.ml
@@ -563,7 +563,11 @@ let from_1_3_dev2_to_1_3_dev5 ~on_the_fly:_ root conf =
             OpamStd.Option.default
               (OpamFile.Descr.create
                  "Switch relying on a system-wide installation of OCaml")
-              (OpamFile.Descr.read_opt descr_f)
+              (if OpamFile.exists descr_f then
+                 Some (OpamFile.Descr.create
+                         (OpamSystem.read (OpamFile.to_string descr_f)))
+               else
+                 None)
           in
           let comp_opam =
             OpamFile.Comp.to_package comp (Some descr)
diff --git a/src/state/opamUpdate.ml b/src/state/opamUpdate.ml
index c62a54eb23b..15fa75f62c0 100644
--- a/src/state/opamUpdate.ml
+++ b/src/state/opamUpdate.ml
@@ -331,12 +331,7 @@ let pinned_package st ?version ?(autolock=false) ?(working_dir=false) name =
     let save_overlay opam =
       OpamFilename.mkdir overlay_dir;
       let opam_file = OpamPath.Switch.Overlay.opam root st.switch name in
-      List.iter OpamFilename.remove
-        OpamPath.Switch.Overlay.([
-            OpamFile.filename opam_file;
-            OpamFile.filename (url root st.switch name);
-            OpamFile.filename (descr root st.switch name);
-          ]);
+      OpamFilename.remove (OpamFile.filename opam_file);
       let files_dir = OpamPath.Switch.Overlay.files root st.switch name in
       OpamFilename.rmdir files_dir;
       let opam =
diff --git a/src/tools/opam_admin_top.ml b/src/tools/opam_admin_top.ml
index e0e19c28091..e088dbe404c 100644
--- a/src/tools/opam_admin_top.ml
+++ b/src/tools/opam_admin_top.ml
@@ -52,30 +52,20 @@ let iter_packages_gen ?(quiet=false) f =
           (OpamPackage.to_string package);
       let opam_file = OpamRepositoryPath.opam repo prefix package in
       let opam = OpamFile.OPAM.read opam_file in
-      let descr_file = OpamRepositoryPath.descr repo prefix package in
-      let descr = OpamFile.Descr.read_opt descr_file in
-      let url_file = OpamRepositoryPath.url repo prefix package in
-      let url = OpamFile.URL.read_opt url_file in
       let dot_install_file : OpamFile.Dot_install.t OpamFile.t =
         OpamFile.make
           (OpamRepositoryPath.files repo prefix package
            // (OpamPackage.Name.to_string (OpamPackage.name package) ^ ".install"))
       in
       let dot_install = OpamFile.Dot_install.read_opt dot_install_file in
-      let opam2, descr2, url2, dot_install2 =
-        f package ~prefix ~opam ~descr ~url ~dot_install
+      let opam2, dot_install2 =
+        f package ~prefix ~opam ~dot_install
       in
-      let descr2 = of_action descr descr2 in
-      let url2 = of_action url url2 in
       let dot_install2 = of_action dot_install dot_install2 in
       let changed = ref false in
       let upd () = changed := true; incr changed_files in
       if opam <> opam2 then
         (upd (); OpamFile.OPAM.write_with_preserved_format opam_file opam2);
-      if descr <> descr2 then
-        (upd (); wopt OpamFile.Descr.write descr_file descr2);
-      if url <> url2 then
-        (upd (); wopt OpamFile.URL.write url_file url2);
       if dot_install <> dot_install2 then
         (upd (); wopt OpamFile.Dot_install.write dot_install_file dot_install2);
       if !changed then
@@ -92,16 +82,15 @@ let iter_packages_gen ?(quiet=false) f =
       !changed_files !changed_pkgs
 
 let iter_packages ?quiet
-    ?(filter=true_) ?f ?(opam=identity) ?descr ?url ?dot_install
+    ?(filter=true_) ?f ?(opam=identity) ?dot_install
     () =
   iter_packages_gen ?quiet
-    (fun p ~prefix ~opam:o ~descr:d ~url:u ~dot_install:i ->
+    (fun p ~prefix ~opam:o ~dot_install:i ->
       if filter p then (
         apply f p prefix o;
-        opam p o, to_action descr p d , to_action url p u,
-        to_action dot_install p i
+        opam p o, to_action dot_install p i
       ) else
-        o, `Keep, `Keep, `Keep)
+        o, `Keep)
 
 let regexps_of_patterns patterns =
   let contains_dot str =
diff --git a/src/tools/opam_admin_top.mli b/src/tools/opam_admin_top.mli
index 84dd93e1e62..cae07c59ab0 100644
--- a/src/tools/opam_admin_top.mli
+++ b/src/tools/opam_admin_top.mli
@@ -28,10 +28,8 @@ val iter_packages_gen:
   (OpamPackage.t ->
    prefix:string option ->
    opam:OPAM.t ->
-   descr:Descr.t option ->
-   url:URL.t option ->
    dot_install:Dot_install.t option ->
-   OPAM.t * Descr.t action * URL.t action * Dot_install.t action)
+   OPAM.t * Dot_install.t action)
   -> unit
 
 (** Turn a list of glob patterns into a proper filtering function on
@@ -44,7 +42,5 @@ val iter_packages:
   ?filter:(OpamPackage.t -> bool) ->
   ?f:(OpamPackage.t -> string option -> OPAM.t -> unit) ->
   ?opam:(OpamPackage.t -> OPAM.t -> OPAM.t) ->
-  ?descr:(OpamPackage.t -> Descr.t -> Descr.t) ->
-  ?url:(OpamPackage.t -> URL.t -> URL.t) ->
   ?dot_install:(OpamPackage.t -> Dot_install.t -> Dot_install.t) ->
   unit -> unit