diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 086e92f7f7eb50516234116070c5217430ba231f..356dd2b36441ee4d7fd61b580d119eabd4d4547e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -27,7 +27,7 @@ eslint:
   script:
     - npm install
     # eslint exits 0 on warnings, this is a workaround to exit 1 when warnings are present.
-    - "! npm run lint | tee /dev/tty | grep -qE '✖ [0-9]+ problem'"
+    - '! npm run lint | tee "$(tty)" | grep -qE ''✖ [0-9]+ problem'''
   allow_failure: true
   needs: []