diff --git a/nix/default.nix b/nix/default.nix
index 7c744b3f6a3e7fea2da96a17977527f4e1e17bef..da1dfba417f576361afddbdd8965fee352a23bc4 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -1,13 +1,13 @@
 # paramaterised derivation with dependencies injected (callPackage style)
 { pkgs, stdenv, opam2nix,
   src ? ../.,
-  ocaml_version ? "ocamlPackages_latest.ocaml",
+  ocaml ? "ocamlPackages_latest.ocaml",
   plugins ? { },
   plugin_extend ? self: super: { }
 }:
 
 plugins.helpers.simple_plugin
-  { inherit pkgs stdenv src opam2nix ocaml_version plugins plugin_extend;
+  { inherit pkgs stdenv src opam2nix ocaml plugins plugin_extend;
     name = "meta";
     deps = [ pkgs.swiProlog ];
     preFramaCTests = ''
diff --git a/nix/frama-ci.nix b/nix/frama-ci.nix
index c7ee97ff4a0577291f3f3a6b179c3bc0a732921a..e083c89e2cd9b2e2f16c123ea6bb1f03598e8b42 100644
--- a/nix/frama-ci.nix
+++ b/nix/frama-ci.nix
@@ -1,13 +1,14 @@
 #To copy in other repository
-{ pkgs, password}:
+{ password}:
 
 let
     src = builtins.fetchGit {
             "url" = "https://bobot:${password}@git.frama-c.com/frama-c/Frama-CI.git";
             "name" = "Frama-CI";
-            "rev" = "f86e807d6f440ac4479b78f8419dfd817803419d";
-            "ref" = "feature/wp/versions-bump";
+            "rev" = "c573f802c66f3821d0bac5f0b71eceaed26b26f1";
+            "ref" = "feature/upgrade-opam2nix";
     };
+    pkgs = import "${src}/pkgs.nix" {};
  in
  {
   src = src;