diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3c5f50a..cc8bbbb 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -7,9 +7,7 @@ check-fmt:
   stage: format
   image: nixos/nix:latest
   script:
-    - nix-shell
-    - make fmt
-    - git diff --quiet
+    - nix-shell --run "make fmt && git diff --quiet"
 
 run-tests:
   stage: test