diff --git a/nix/frama-ci.nix b/nix/frama-ci.nix
index 65141e9684de9637e600df87397aeb97366afdbf..e99207aef5994e066c9c9fadfc18e6024bdee7ec 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" = "f86e807d6f440ac4479b78f8419dfd817803419d";
-            "ref" = "feature/wp/versions-bump";
+            "rev" = "4c154fc4d99e26ea9987750103938c059398b5ea";
+            "ref" = "feature/upgrade-opam2nix";
     };
  in
  {