diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 13dd6ad59e19c6977f78a443bfc556d68519ec9e..4767d4b4975ca5698dad7790237f8540e8769912 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -26,7 +26,7 @@ unit-tests:
   script:
     - |
       # GRID is set in one of the "instantiations" of this job template.
-      nix-shell --command "morph build morph/grid/${GRID}/grid.nix
+      nix-shell --run "morph build morph/grid/${GRID}/grid.nix
 
 
 morph-build-localdev: