diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 87d65d5591a26341fecf9f5c8e2e77512a365b82..d2b59ffda31d10d5693809ea9105c74c7e2564bf 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -67,7 +67,7 @@ genassigns:
 frama-clang:
   stage: tests
   script:
-   - nix/frama-ci.sh build -A frama-clang.tests
+   - nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/0c0fe6d85b92c4e992e314bd6f9943413af9a309.tar.gz -p nix --run "nix/frama-ci.sh build -A frama-clang.tests"
   tags:
    - nix