diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b4e9c55df4405df312413ccbf2b145be50742c14..2044ffdcf4b9b60434a86fb1eeae4e233f6b36ad 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -504,7 +504,7 @@ ocaml-versions-nightly:
   image: 'ocaml/opam:ubuntu-20.04-ocaml-$OCAML'
   script:
     - sudo apt update
-    - opam pin . -n
+    - opam pin . -n -k path
     - opam depext frama-c --with-test
     - opam install --jobs 2 frama-c --with-test --with-doc
     - frama-c --plugins