diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bd4bea5e5..17c49fd94 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,6 +27,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
+        coq: [coq-8-18, coq-8-19, coq-master]
     runs-on: ${{ matrix.os }}
     steps:
     - name: Checkout
@@ -41,7 +42,7 @@ jobs:
     - uses: cachix/install-nix-action@v22
       with:
         nix_path: nixpkgs=channel:nixos-unstable
-    - run: nix develop .#vscoq-language-server -c bash -c "cd language-server && dune build"
+    - run: nix develop .#vscoq-language-server-${{ matrix.coq }} -c bash -c "cd language-server && dune build"
     - run: nix develop .#vscoq-client -c bash -c "cd client && yarn run install:all && yarn run build:all && yarn run compile"
     - run: xvfb-run nix develop .#vscoq-client -c bash -c "cd client && yarn test"
       if: runner.os == 'Linux'
@@ -52,9 +53,11 @@ jobs:
 
   install-opam:
     strategy:
+      fail-fast: false
       matrix:
         os: [ubuntu-latest]
         ocaml-compiler: [4.13.x]
+        coq: [8.18.0, 8.19+rc1, dev]
     runs-on: ${{ matrix.os }}
     steps:
     - name: Checkout
@@ -70,6 +73,7 @@ jobs:
         OPAMYES: true
       run: |
         opam repo add coq-core-dev https://coq.inria.fr/opam/core-dev
+        opam install coq-core.${{ matrix.coq }}
         opam pin add vscoq-language-server ./language-server/ --with-doc --with-test -y
 
     - run: |
diff --git a/flake.lock b/flake.lock
index cb783bbf3..e25910e35 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,9 +1,49 @@
 {
   "nodes": {
+    "coq-master": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1707209540,
+        "narHash": "sha256-C3ZnIXZQptLo76iqltf/GYu/EqFU5yT7nSMClKTriiI=",
+        "owner": "coq",
+        "repo": "coq",
+        "rev": "b157d65080076498ad04dd3918c1e508eb9740c0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "coq",
+        "repo": "coq",
+        "rev": "b157d65080076498ad04dd3918c1e508eb9740c0",
+        "type": "github"
+      }
+    },
     "flake-utils": {
       "inputs": {
         "systems": "systems"
       },
+      "locked": {
+        "lastModified": 1681202837,
+        "narHash": "sha256-H+Rh19JDwRtpVPAWp64F+rlEtxUWBAQW28eAi3SRSzg=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "cfacdce06f30d2b68473a46042957675eebb3401",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
       "locked": {
         "lastModified": 1705309234,
         "narHash": "sha256-uNRRNRKmJyCRC/8y1RqBkqWBLM034y4qN7EprSdmgyA=",
@@ -34,7 +74,8 @@
     },
     "root": {
       "inputs": {
-        "flake-utils": "flake-utils",
+        "coq-master": "coq-master",
+        "flake-utils": "flake-utils_2",
         "nixpkgs": "nixpkgs"
       }
     },
@@ -52,6 +93,21 @@
         "repo": "default",
         "type": "github"
       }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",
diff --git a/flake.nix b/flake.nix
index f8680278e..89bcc24eb 100644
--- a/flake.nix
+++ b/flake.nix
@@ -5,16 +5,88 @@
 
     flake-utils.url = "github:numtide/flake-utils";
 
+    coq-master = { url = "github:coq/coq/b157d65080076498ad04dd3918c1e508eb9740c0"; }; # Should be kept in sync with PIN_COQ in CI workflow
+    coq-master.inputs.nixpkgs.follows = "nixpkgs";
+
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
+  outputs = { self, nixpkgs, flake-utils, coq-master }:
     flake-utils.lib.eachDefaultSystem (system:
   
+   let coq = coq-master.defaultPackage.${system}; in
    rec {
 
-    packages.default = self.packages.${system}.vscoq-language-server;
+    packages.default = self.packages.${system}.vscoq-language-server-coq-8-19;
+
+    packages.vscoq-language-server-coq-8-18 =
+      # Notice the reference to nixpkgs here.
+      with import nixpkgs { inherit system; };
+      let ocamlPackages = ocaml-ng.ocamlPackages_4_14; in
+      ocamlPackages.buildDunePackage {
+        duneVersion = "3";
+        pname = "vscoq-language-server";
+        version = "2.0.3";
+        src = ./language-server;
+        buildInputs = [
+          coq_8_18
+          dune_3
+        ] ++ (with coq.ocamlPackages; [
+          lablgtk3-sourceview3
+          glib
+          gnome.adwaita-icon-theme
+          wrapGAppsHook
+          ocaml
+          yojson
+          zarith
+          findlib
+          ppx_inline_test
+          ppx_assert
+          ppx_sexp_conv
+          ppx_deriving
+          ppx_optcomp
+          ppx_import
+          sexplib
+          ppx_yojson_conv
+          lsp
+          sel
+        ]);
+      };
+
+      packages.vscoq-language-server-coq-8-19 =
+      # Notice the reference to nixpkgs here.
+      with import nixpkgs { inherit system; };
+      let ocamlPackages = ocaml-ng.ocamlPackages_4_14; in
+      ocamlPackages.buildDunePackage {
+        duneVersion = "3";
+        pname = "vscoq-language-server";
+        version = "2.0.3";
+        src = ./language-server;
+        buildInputs = [
+          coq_8_19
+          dune_3
+        ] ++ (with coq.ocamlPackages; [
+          lablgtk3-sourceview3
+          glib
+          gnome.adwaita-icon-theme
+          wrapGAppsHook
+          ocaml
+          yojson
+          zarith
+          findlib
+          ppx_inline_test
+          ppx_assert
+          ppx_sexp_conv
+          ppx_deriving
+          ppx_optcomp
+          ppx_import
+          sexplib
+          ppx_yojson_conv
+          lsp
+          sel
+        ]);
+      };
 
-    packages.vscoq-language-server =
+    packages.vscoq-language-server-coq-master =
       # Notice the reference to nixpkgs here.
       with import nixpkgs { inherit system; };
       let ocamlPackages = ocaml-ng.ocamlPackages_4_14; in
@@ -39,6 +111,7 @@
           ppx_assert
           ppx_sexp_conv
           ppx_deriving
+          ppx_optcomp
           ppx_import
           sexplib
           ppx_yojson_conv
@@ -61,11 +134,42 @@
 
     };
 
-    devShells.default =
+    devShells.vscoq-client = 
+      with import nixpkgs { inherit system; };
+      mkShell {
+        buildInputs = self.packages.${system}.vscoq-client.buildInputs;
+      };
+
+    devShells.vscoq-language-server-coq-8-18 = 
+        with import nixpkgs { inherit system; };
+        mkShell {
+            buildInputs =
+            self.packages.${system}.vscoq-language-server-coq-8-18.buildInputs;
+        };
+        
+    devShells.vscoq-language-server-coq-8-19 = 
+      with import nixpkgs { inherit system; };
+      mkShell {
+        buildInputs =
+          self.packages.${system}.vscoq-language-server-coq-8-19.buildInputs;
+      };
+    
+    devShells.vscoq-language-server-coq-master = 
+      with import nixpkgs { inherit system; };
+      let ocamlPackages = ocaml-ng.ocamlPackages_4_14; in
+      mkShell {
+        buildInputs =
+          self.packages.${system}.vscoq-language-server-coq-master.buildInputs
+          ++ (with ocamlPackages; [
+            ocaml-lsp
+          ]);
+      };
+
+    devShells.default = 
       with import nixpkgs { inherit system; };
       mkShell {
         buildInputs =
-          self.packages.${system}.vscoq-language-server.buildInputs
+          self.packages.${system}.vscoq-language-server-coq-8-19.buildInputs
           ++ (with ocamlPackages; [
             ocaml-lsp
           ]);
diff --git a/language-server/dm/completionSuggester.ml b/language-server/dm/completionSuggester.ml
index f36f794c9..ecdd40391 100644
--- a/language-server/dm/completionSuggester.ml
+++ b/language-server/dm/completionSuggester.ml
@@ -415,13 +415,18 @@ let get_completion_items env proof lemmas options =
     log ("Ranking of lemmas failed: " ^ (Printexc.to_string e));
     lemmas
 
+[%%if coq = "8.18"]
+let generic_search e s f = Search.generic_search e (fun r k e c -> f r k e s c)
+[%%else]
+let generic_search = Search.generic_search
+[%%endif]
 let get_lemmas sigma env =
   let open CompletionItems in
   let results = ref [] in
-  let display ref _kind env c =
+  let display ref _kind env sigma c =
     results := mk_completion_item sigma ref env c :: results.contents;
   in
-  Search.generic_search env display;
+  generic_search env sigma display;
   results.contents
 
 let get_completions options st =
diff --git a/language-server/dm/document.ml b/language-server/dm/document.ml
index 075da44f8..edda41a5f 100644
--- a/language-server/dm/document.ml
+++ b/language-server/dm/document.ml
@@ -252,6 +252,12 @@ let rec junk_sentence_end stream =
   | [] -> ()
   | _ ->  Stream.junk () stream; junk_sentence_end stream
 
+[%%if coq = "8.18"]
+exception E = Stream.Error
+[%%else]
+exception E = Grammar.Error
+[%%endif]
+
 let rec parse_more synterp_state stream raw parsed errors =
   let handle_parse_error start msg =
     log @@ "handling parse error at " ^ string_of_int start;
@@ -290,7 +296,7 @@ let rec parse_more synterp_state stream raw parsed errors =
           let loc = Loc.get_loc @@ info in
           handle_parse_error start (loc, Pp.string_of_ppcmds @@ CErrors.iprint_no_report (e,info))
         end
-    | exception (Stream.Error msg as exn) ->
+    | exception (E msg as exn) ->
       let loc = Loc.get_loc @@ Exninfo.info exn in
       junk_sentence_end stream;
       handle_parse_error start (loc,msg)
@@ -388,4 +394,4 @@ module Internal = struct
     sentence.start
     sentence.stop
 
-end
\ No newline at end of file
+end
diff --git a/language-server/dm/dune b/language-server/dm/dune
index 4dc1c7f49..151794fa5 100644
--- a/language-server/dm/dune
+++ b/language-server/dm/dune
@@ -2,6 +2,7 @@
  (name dm)
  (public_name vscoq-language-server.dm)
  (modules :standard \ vscoqtop_proof_worker vscoqtop_tactic_worker)
+ (preprocess (pps ppx_optcomp -- -cookie "ppx_optcomp.env=env ~coq:(Defined \"%{coq:version.major}.%{coq:version.minor}\")"))
  (libraries base coq-core.sysinit coq-core.vernac coq-core.parsing lsp sel protocol language))
 
 (executable
diff --git a/language-server/dm/executionManager.ml b/language-server/dm/executionManager.ml
index ce28c38ce..1ad132958 100644
--- a/language-server/dm/executionManager.ml
+++ b/language-server/dm/executionManager.ml
@@ -182,14 +182,22 @@ let interp_ast ~doc_id ~state_id ~st ~error_recovery ast =
         st, status, []
 
 (* This adapts the Future API with our event model *)
+[%%if coq = "8.18"]
+let definition_using e s ~fixnames:_ ~using ~terms =
+  Proof_using.definition_using e s ~using ~terms
+[%%else]
+let definition_using = Proof_using.definition_using
+[%%endif]
 let interp_qed_delayed ~proof_using ~state_id ~st =
+  let lemmas = Option.get @@ st.Vernacstate.interp.lemmas in
   let f proof =
     let proof =
       let env = Global.env () in
       let sigma, _ = Declare.Proof.get_current_context proof in
       let initial_goals pf = Proofview.initial_goals Proof.((data pf).entry) in
       let terms = List.map (fun (_,_,x) -> x) (initial_goals (Declare.Proof.get proof)) in
-      let using = Proof_using.definition_using env sigma ~using:proof_using ~terms in
+      let names = Vernacstate.LemmaStack.get_all_proof_names lemmas in
+      let using = definition_using env sigma ~fixnames:names ~using:proof_using ~terms in
       let vars = Environ.named_context env in
       Names.Id.Set.iter (fun id ->
           if not (List.exists Util.(Context.Named.Declaration.get_id %> Names.Id.equal id) vars) then
@@ -202,7 +210,6 @@ let interp_qed_delayed ~proof_using ~state_id ~st =
     let f, assign = Future.create_delegate ~blocking:false ~name:"XX" fix_exn in
     Declare.Proof.close_future_proof ~feedback_id:state_id proof f, assign
   in
-  let lemmas = Option.get @@ st.Vernacstate.interp.lemmas in
   let proof, assign = Vernacstate.LemmaStack.with_top lemmas ~f in
   let control = [] (* FIXME *) in
   let opaque = Vernacexpr.Opaque in
diff --git a/language-server/dm/parTactic.ml b/language-server/dm/parTactic.ml
index 4f85bace2..169e62bc7 100644
--- a/language-server/dm/parTactic.ml
+++ b/language-server/dm/parTactic.ml
@@ -60,7 +60,11 @@ let assign_tac ~abstract res : unit Proofview.tactic =
       tclUNIT ()
   end)
 
+[%%if coq = "8.18" || coq = "8.19"]
 let command_focus = Proof.new_focus_kind ()
+[%%else]
+let command_focus = Proof.new_focus_kind "vscoq_command_focus"
+[%%endif]
 
 let worker_solve_one_goal { TacticJob.state; ast; goalno; goal } ~send_back =
   let focus_cond = Proof.no_cond command_focus in
diff --git a/language-server/dm/searchQuery.ml b/language-server/dm/searchQuery.ml
index 50ce2fbe6..803f2789a 100644
--- a/language-server/dm/searchQuery.ml
+++ b/language-server/dm/searchQuery.ml
@@ -15,8 +15,7 @@ open Util
 open Printer
 open Protocol.Printing
 open Protocol.LspWrapper
-open Vernacexpr
-open Pp
+
 (* Note: this queue is not very useful today, as we process results in the main
 vscoq process, which does not allow for real asynchronous processing of results. *)
 let query_results_queue = Queue.create ()
@@ -24,6 +23,9 @@ let query_results_queue = Queue.create ()
 let query_feedback : notification Sel.Event.t =
   Sel.On.queue query_results_queue (fun x -> QueryResultNotification x)
 
+[%%if coq = "8.18"]
+open Vernacexpr
+open Pp
 (* TODO : remove these two functions when interp_search_restriction is 
   added in the comSearch.mli in Coq (they're simply copied here for now) *)
 let global_module qid =
@@ -34,20 +36,25 @@ let global_module qid =
 let interp_search_restriction = function
   | SearchOutside l -> (List.map global_module l, true)
   | SearchInside l -> (List.map global_module l, false)
+let adapt_pr_search f r k e c = f r k e (Evd.from_env e) c
+[%%else]
+let interp_search_restriction = ComSearch.interp_search_restriction
+let adapt_pr_search f = f
+[%%endif]
 
 let interp_search ~id env sigma s r =
-  let pr_search ref _kind env c =
-    let name = pr_global ref in
+  let pr_search ref _kind env sigma c =
+    let pr = pr_global ref in
     let open Impargs in
     let impls = implicits_of_global ref in
     let impargs = select_stronger_impargs impls in
     let impargs = List.map binding_kind_of_status impargs in
-    let statement = pr_ltype_env env Evd.(from_env env) ~impargs c in
-    let name = pp_of_coqpp name in
-    let statement = pp_of_coqpp statement in
+    let pc = pr_ltype_env env sigma ~impargs c in
+    let name = pp_of_coqpp pr in
+    let statement = pp_of_coqpp pc in
     Queue.push { id; name; statement } query_results_queue
   in
   let r = interp_search_restriction r in
-  (Search.search env sigma (List.map (ComSearch.interp_search_request env Evd.(from_env env)) s) r |>
-    Search.prioritize_search) pr_search;
+  (Search.search env sigma (List.map (ComSearch.interp_search_request env sigma) s) r |>
+    Search.prioritize_search) (adapt_pr_search pr_search);
   [query_feedback]
diff --git a/language-server/dm/searchQuery.mli b/language-server/dm/searchQuery.mli
index 5818b5962..e44a51087 100644
--- a/language-server/dm/searchQuery.mli
+++ b/language-server/dm/searchQuery.mli
@@ -15,6 +15,7 @@ open Protocol.LspWrapper
 
 val query_feedback : notification Sel.Event.t
 
+[%%if coq = "8.18"]
 val interp_search :
   id:string ->
   Environ.env ->
@@ -22,3 +23,12 @@ val interp_search :
   (bool * Vernacexpr.search_request) list ->
   Vernacexpr.search_restriction ->
   notification Sel.Event.t list
+[%%else]
+val interp_search :
+  id:string ->
+  Environ.env ->
+  Evd.evar_map ->
+  (bool * Vernacexpr.search_request) list ->
+  Libnames.qualid list Vernacexpr.search_restriction ->
+  notification Sel.Event.t list
+[%%endif]
diff --git a/language-server/language/dune b/language-server/language/dune
index aad9afdda..5c69f412e 100644
--- a/language-server/language/dune
+++ b/language-server/language/dune
@@ -1,4 +1,5 @@
 (library
  (name language)
  (public_name vscoq-language-server.language)
+ (preprocess (pps ppx_optcomp -- -cookie "ppx_optcomp.env=env ~coq:(Defined \"%{coq:version.major}.%{coq:version.minor}\")"))
  (libraries coq-core.sysinit lsp))
\ No newline at end of file
diff --git a/language-server/language/hover.ml b/language-server/language/hover.ml
index add6da727..ec205be80 100644
--- a/language-server/language/hover.ml
+++ b/language-server/language/hover.ml
@@ -38,9 +38,31 @@ let compactify s =
   List.fold_left (fun s (reg,repl) -> Str.global_replace reg repl s) s replacements
 
 (* TODO this should be exposed by Coq and removed from here *)
+
+[%%if coq = "8.18"]
+let pr_s = prlist (fun CAst.{v=s} -> str "%" ++ str s)
+let eq_realarg = List.equal (fun a b -> String.equal a.CAst.v b.CAst.v)
+let nargs_maximal_of_pos ((na,_,_),_,(maximal,_)) = na, maximal
+let make_scope = CAst.make
+[%%else]
+let pr_delimiter_depth = function
+  | Constrexpr.DelimOnlyTmpScope -> str "%_"
+  | Constrexpr.DelimUnboundedScope -> str "%"
+let pr_scope_delimiter (d, sc) = pr_delimiter_depth d ++ str sc
+let pr_s = prlist (fun CAst.{v=s} -> pr_scope_delimiter s)
+
+let eq_realarg =
+  List.equal
+   (fun a b -> let da, a = a.CAst.v in let db, b = b.CAst.v in
+    da = db && String.equal a b)
+let nargs_maximal_of_pos imp =
+  let (na, _, _) = imp.Impargs.impl_pos in
+  na, imp.Impargs.impl_max
+let make_scope = (fun s -> CAst.make (Constrexpr.DelimUnboundedScope, s))
+[%%endif]
+
 let pr_args args more_implicits mods =
   let open Vernacexpr in
-  let pr_s = prlist (fun CAst.{v=s} -> str "%" ++ str s) in
   let pr_if b x = if b then x else str "" in
   let pr_one_arg (x,k) = pr_if k (str"!") ++ Name.print x in
   let pr_br imp force x =
@@ -56,8 +78,7 @@ let pr_args args more_implicits mods =
     if s = [] && imp = Glob_term.Explicit then [], tl
     else
       let rec fold extra = function
-        | RealArg arg :: tl when
-            List.equal (fun a b -> String.equal a.CAst.v b.CAst.v) arg.notation_scope s
+        | RealArg arg :: tl when eq_realarg arg.notation_scope s
             && arg.implicit_status = imp ->
           fold ((arg.name,arg.recarg_like) :: extra) tl
         | args -> List.rev extra, args
@@ -99,7 +120,9 @@ let pr_args args more_implicits mods =
 
 let implicit_kind_of_status = function
   | None -> Anonymous, Glob_term.Explicit
-  | Some ((na,_,_),_,(maximal,_)) -> na, if maximal then Glob_term.MaxImplicit else Glob_term.NonMaxImplicit
+  | Some imp ->
+    let na, maximal = nargs_maximal_of_pos imp in
+    na, if maximal then Glob_term.MaxImplicit else Glob_term.NonMaxImplicit
 
 let extra_implicit_kind_of_status imp =
   let _,imp = implicit_kind_of_status imp in
@@ -131,7 +154,7 @@ let rec main_implicits i renames recargs scopes impls =
       | [], (None::_ | []) -> (Anonymous, Glob_term.Explicit)
     in
     let notation_scope = match scopes with
-      | scope :: _ -> List.map CAst.make scope
+      | scope :: _ -> List.map make_scope scope
       | [] -> []
     in
     let status = {Vernacexpr.implicit_status; name; recarg_like; notation_scope} in
@@ -166,14 +189,26 @@ let rec insert_fake_args volatile bidi impls =
     let f = Option.map pred in
     RealArg hd :: insert_fake_args (f volatile) (f bidi) tl
 
+[%%if coq = "8.18"]
+let ref_of_const x = Some x
+[%%else]
+let ref_of_const = function
+| GlobRef.ConstRef ref -> Some ref
+| _ -> None
+[%%endif]
+
 let print_arguments ref =
   let flags, recargs, nargs_for_red =
     let open Reductionops.ReductionBehaviour in
-    match get ref with
+    match ref_of_const ref with
+    | Some ref ->
+      begin match get ref with
+      | None -> [], [], None
+      | Some NeverUnfold -> [`ReductionNeverUnfold], [], None
+      | Some (UnfoldWhen { nargs; recargs }) -> [], recargs, nargs
+      | Some (UnfoldWhenNoMatch { nargs; recargs }) -> [`ReductionDontExposeCase], recargs, nargs
+      end
     | None -> [], [], None
-    | Some NeverUnfold -> [`ReductionNeverUnfold], [], None
-    | Some (UnfoldWhen { nargs; recargs }) -> [], recargs, nargs
-    | Some (UnfoldWhenNoMatch { nargs; recargs }) -> [`ReductionDontExposeCase], recargs, nargs
   in
   let names, not_renamed =
     try Arguments_renaming.arguments_names ref, false
@@ -260,4 +295,4 @@ let get_hover_contents env sigma ref_or_by_not =
     end
     in
     Option.map Lsp.Types.(fun value -> MarkupContent.create ~kind:MarkupKind.Markdown ~value) r
-  | Constrexpr.ByNotation (_ntn,_sc) -> assert false
\ No newline at end of file
+  | Constrexpr.ByNotation (_ntn,_sc) -> assert false
diff --git a/language-server/vscoq-language-server.opam b/language-server/vscoq-language-server.opam
index ba508be1e..9a7e05c9b 100644
--- a/language-server/vscoq-language-server.opam
+++ b/language-server/vscoq-language-server.opam
@@ -12,9 +12,9 @@ build: [
 ]
 depends: [
   "ocaml" { >= "4.13.1" }
-  "dune" { >= "3.2" }
-  "coq-core" { >= "8.18" < "8.19" }
-  "coq-stdlib" { >= "8.18" < "8.19" }
+  "dune" { >= "3.5" }
+  "coq-core" { >= "8.18" < "8.20" }
+  "coq-stdlib" { >= "8.18" < "8.20" }
   "yojson"
   "jsonrpc" { >= "1.15"}
   "ocamlfind"
@@ -26,6 +26,7 @@ depends: [
   "sexplib"
   "ppx_yojson_conv"
   "ppx_import"
+  "ppx_optcomp"
   "result" { >= "1.5" }
   "lsp" { >= "1.15"}
   "sel" {>= "0.4.0"}