diff --git a/nix/default.nix b/nix/default.nix
index f19ba93881d07f8373098fec81711ed68be143e3..b75d189f7cb80fe2a5c56ecb70a5d5cc47369741 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -4,14 +4,13 @@
 let mk_buildInputs = { opamPackages ? [], nixPackages ? [] } :
     [ pkgs.gnugrep pkgs.gnused  pkgs.autoconf pkgs.gnumake pkgs.gcc pkgs.ncurses pkgs.time pkgs.python3 pkgs.perl pkgs.file] ++ nixPackages ++ opam2nix.build {
            specs = opam2nix.toSpecs ([ "ocamlfind" "zarith" "ocamlgraph" "yojson"
-                { name = "coq"; constraint = "=8.11.0";  }
+                { name = "coq"; constraint = "=8.10.2";  }
                 { name = "why3" ; constraint = "=1.3.1"; }
                 { name = "why3-coq" ; constraint = "=1.3.1"; }
-                { name = "menhir"; constraint = "=20181113"; }
+                { name = "menhir"; constraint = "=20190924"; }
+                { name = "dune"; constraint = "=1.11.4"; }
                 "camlzip" #so that why3 is always compiled with it
-                ] ++ opamPackages ++
-                (if ocaml_version == "pkgs.ocaml-ng.ocamlPackages_4_02.ocaml"
-                then [ { name = "ocamlbuild" ; constraint = "=0"; } ] else [])
+                ] ++ opamPackages
               );
            ocamlAttr = ocaml_version;
         };
diff --git a/nix/frama-ci.nix b/nix/frama-ci.nix
index fb32fb772345f36d509b68e0ef3ea04213545105..b022dab5948f5ff9a43553e57cc0ff13663d796a 100644
--- a/nix/frama-ci.nix
+++ b/nix/frama-ci.nix
@@ -5,8 +5,8 @@ let
     src = builtins.fetchGit {
             "url" = "https://bobot:${password}@git.frama-c.com/frama-c/Frama-CI.git";
             "name" = "Frama-CI";
-            "rev" = "cea0f2d2872e59fd3e6fe4634891a3765c7036e8";
-            "ref" = "feature/opam2";
+            "rev" = "79089bda56f3398fabd5269d7270f1330326de99";
+            "ref" = "feature/ci/update-opam";
     };
  in
  {