diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 874f560ff9a196676910373e632362cb618fbe9b..340a1fe96a11a5b71629ccc21292acb2a43719da 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -49,9 +49,11 @@ morph-builds:
 
   script:
     - |
+      nix-shell --command '
       for grid in morph/grid/*/grid.nix; do
           morph build "${grid}"
       done
+      '
 
   after_script:
     - |