diff --git a/.github/workflows/proof_tools.yml b/.github/workflows/proof_tools.yml
index 9b94bccb0cd3d29e6fcfa2b1cf84dc5ef1bdcc41..88e04f6193ad92ab76c62c3720edbd0f6ebe9065 100644
--- a/.github/workflows/proof_tools.yml
+++ b/.github/workflows/proof_tools.yml
@@ -15,8 +15,6 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-      with:
-        path: personoj
 
     - name: Use ocaml
       uses: ocaml/setup-ocaml@v2
@@ -28,7 +26,7 @@ jobs:
 
     - name: toolbox
       run: |
-        cd "${GITHUB_WORKSPACE}"/personoj/proofs/psnj_toolbox || exit 1
+        cd proofs/psnj_toolbox || exit 1
         opam install . --deps-only --yes
         opam exec -- dune build
         opam exe -- dune runtest
@@ -42,8 +40,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-      with:
-        path: personoj
 
     - name: ocaml
       uses: ocaml/setup-ocaml@v2
@@ -59,13 +55,13 @@ jobs:
     - name: install tools
       run: |
         opam install yojson angstrom feather cmdliner
-        cd "${GITHUB_WORKSPACE}"/personoj/proofs || exit 1
+        cd proofs || exit 1
         (cd split && bmake && sudo bmake install)
         (cd pipeline && bmake && sudo bmake install)
         (cd psnj_toolbox && make && sudo make install)
 
     - name: launch pipeline
       run: |
-        cd "${GITHUB_WORKSPACE}"/personoj/proofs/pipeline || exit 1
+        cd proofs/pipeline || exit 1
         bmake tests
 
diff --git a/proofs/psnj_toolbox/personoj.opam.locked b/proofs/psnj_toolbox/personoj.opam.locked
new file mode 100644
index 0000000000000000000000000000000000000000..6aa761bd5665610a74ee5445505a650b31dfb0f6
--- /dev/null
+++ b/proofs/psnj_toolbox/personoj.opam.locked
@@ -0,0 +1,67 @@
+opam-version: "2.0"
+name: "personoj"
+version: "~dev"
+synopsis: "todo"
+depends: [
+  "angstrom" {= "0.15.0"}
+  "base" {= "v0.14.2"}
+  "base-bigarray" {= "base"}
+  "base-bytes" {= "base"}
+  "base-threads" {= "base"}
+  "base-unix" {= "base"}
+  "bigarray-compat" {= "1.0.0"}
+  "bigstringaf" {= "0.8.0"}
+  "bindlib" {= "5.0.1"}
+  "biniou" {= "1.2.1"}
+  "cmdliner" {= "1.0.4"}
+  "conf-pkg-config" {= "2"}
+  "cppo" {= "1.6.8"}
+  "csexp" {= "1.5.1"}
+  "dune" {= "2.9.1"}
+  "dune-configurator" {= "2.9.1"}
+  "easy-format" {= "1.3.2"}
+  "gen" {= "0.5.3"}
+  "lambdapi" {= "1.0"}
+  "menhir" {= "20211128"}
+  "menhirLib" {= "20211128"}
+  "menhirSdk" {= "20211128"}
+  "num" {= "1.4"}
+  "ocaml" {= "4.11.1"}
+  "ocaml-compiler-libs" {= "v0.12.4"}
+  "ocaml-config" {= "1"}
+  "ocaml-syntax-shims" {= "1.0.0"}
+  "ocaml-system" {= "4.11.1"}
+  "ocamlbuild" {= "0.14.0"}
+  "ocamlfind" {= "1.9.1"}
+  "ppx_derivers" {= "1.2.1"}
+  "ppx_sexp_conv" {= "v0.14.3"}
+  "ppxlib" {= "0.23.0"}
+  "pratter" {= "1.2"}
+  "re" {= "1.10.3"}
+  "result" {= "1.5"}
+  "sedlex" {= "2.5"}
+  "seq" {= "base"}
+  "sexplib0" {= "v0.14.0"}
+  "stdlib-shims" {= "0.3.0"}
+  "timed" {= "1.0"}
+  "uchar" {= "0.0.2"}
+  "why3" {= "1.4.0"}
+  "yojson" {= "1.7.0"}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "--promote-install-files=false"
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+  ["dune" "install" "-p" name "--create-install-files" name]
+]
+pin-depends: ["lambdapi.1.0" "git://github.com/gabrielhdt/lambdapi#refiner"]
\ No newline at end of file